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US-Israeli Symposium on C1 Chemistry :
08:00am - 09:30am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Aditya Bhan, Organizer, Univ of Minnesota; Oz M Gazit, Organizer, Technion; Prof. Dmitri Gelman, Organizer, The Hebrew University of Jerusalem; Daniel Resasco, Organizer, University of Oklahoma; Daniel Resasco, Presider, University of Oklahoma; Aditya Bhan, Presider, Univ of Minnesota
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Division/Committee: [CATL] Division of Catalysis Science & Technology

This symposium explores the topic of C1 conversion in context of the broader chemical enterprise. Presentations will feature research at the state-of-the-art in electrochemical and thermochemical upgrading of C1 species to fuels and chemicals.

Sunday
Catalytic activation of light alkanes on promoted molybdenum oxide catalysts: Coupling of catalytic rates and their mechanistic implications
08:00am - 08:30am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Catalytic conversions of light alkanes to their corresponding olefins are attractive routes for utilizing natural gas feedstocks. Starting with ethane, its reaction produces ethylene as the platform molecule for sequential synthesis of a wide variety of commodity chemicals, including polyethylene, styrene, ethylene oxide, and ethylene glycol. Its catalytic turnovers occur either without a co-oxidant via dehydrogenation or with O2 or CO2 via oxidative dehydrogenation reactions. Herein, we will unravel the mechanistic similarities and differences among the various ethane conversion reactions, on two-dimensional MoOx dispersed on Al2O3 catalysts promoted by Fe, Co, or Ni catalysts. These reactions, irrespective of the presence of or the chemical identity of the co-reactant, occur via the common step, that the initial C-H bond activation of ethane limits rates. The ethane activation cycle is catalytically coupled with the oxidant activation cycle, the latter generates reactive oxygen species that scavenge the surface carbon debris and therefore retain the catalytic reactivity and stability. We will discuss these catalytic cycles among the different ethane conversion catalysis, the key catalytic events, and their periodic reactivity trends, when incorporating the earth abundant Fe, Co, and Ni transition metal into the dispersed MoOx structures. More specifically, we will discuss how these metal cations could alter the catalytic rates of the various, concomitant catalytic cycles, interjecting deactivation, leading to the observed rates and selectivities. We attempt to provide consolidate mechanistic framework, accounting for both the rates as well as the time-dependent rate decay for ethane reactions for the series of catalyst materials.
Sunday
Multi-phase catalysts for stable methane cracking and reforming
08:30am - 09:00am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Prof. Brian A. Rosen, Presenter, Tel Aviv University
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Defective solid-catalysts and multi-phase catalysts are intriguing materials which would pave the way towards stable methane cracking and reforming. While point defects have been well studied in energy conversion ceramics by exploiting non-isovalent lattice substitutions and non-stoichiometric compounds, the impact of multidimensional defects on catalytic activity and stability is far less studied. During activation, energy conversion catalysts often go through solid-state phase transitions. These transitions can either be beneficial or detrimental to performance. We observe that extended defects critically impacts the temperature at which such phase transitions can occur, the pathway of the phase transition, and resulting catalytic activity and stability of the catalyst. Extended defects such as stacking faults in substituted lanthanum nickelates and lanthanum ferrates can be exploited to significantly extend catalyst lifetimes and lower apparent activation energy for critical reactions such as methane and carbon monoxide oxidation. Furthermore, multi-phase catalysts involving solid-liquid equilibrium are also exploited to imbue stable methane cracking with increased performance.
Sunday
Elucidating and controlling the selective electrocatalytic reduction of CO2 to C1 chemical intermediates
09:00am - 09:30am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Matthew Neurock, Presenter
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
The development of sustainable strategies to meet the world’s increasing energy demands will require the use of renewable energy sources together with carbon-neutral and energy efficient processes that can significantly reduce CO2 emissions. The sustainable catalytic conversion of CO2 to carbon monoxide as well as formic acid and their subsequent transformation to fuels and chemical intermediates offer attractive routes to carbon-neutral fuels. Nature readily carries out these reactions out with very high selectivities by co-locating the active metal centers within highly reactive reaction cavities. Recent experimental results show that the CO2 can be efficiently reduced over various late transition metals within ionic liquid as well as within alkaline media. The metal-electrolyte-solvent interface plays a critical role in enhanced the CO2 reduction and selectively forming either CO or formic acid produces.
Novel potential-dependent ab initio molecular dynamics simulations are carried out herein to help unravel the elementary steps and the mechanisms that govern these transformations and to show how changes in the solvent, electrolyte, pH and potential drive the activity as well as the selectivity in these systems. We show how changes in the potential and the reaction conditions can drive the formation of unique electrolyte, solvent, reactant environments that readily facilitate the rate controlling electron transfer reaction and selectively guide the subsequent proton addition to exclusively form CO or formic acid products. The simulations combined with experiments show that subtle changes in the electrolyte and the solvent can be used to dictate the formation of CO or formic acid with Faradaic Efficiencies of > 97 %. The simulations are used to help identify important electrolyte and metal catalysts systems as well as mixed electrolyte systems that will drive the active and selective formation to C1 products.

Carbon Capture & Utilization: Conversion of CO2 to Chemicals & Fuels:
08:00am - 10:00am USA / Canada - Eastern - August 22, 2021 | Room: B218
Juliana Carneiro, Organizer, Georgia Institute of Technology; Kandis Gilliard-AbdulAziz, Organizer, University of California Riverside; Ambarish Kulkarni, Organizer, University of California Davis; Kandis Gilliard-AbdulAziz, Presider, University of California Riverside; Juliana Carneiro, Presider, ‍ ; Ambarish Kulkarni, Presider, University of California Davis
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Division/Committee: [CATL] Division of Catalysis Science & Technology

Carbon Capture and Utilization (CCU) is seen as a means to mitigate the emissions of CO2 with the concomitant use of a catalytic component for the conversion of CO2 to fuels, chemicals and polymers. While research for CO2 capture and utilization can be broad, this symposium will focus on the thermocatalytic and electrocatalytic strategies for CO2 capture and utilization. This symposium will foster the discussion from different perspectives and provide insights to address existing challenges in advancing these technologies further.

Sunday
CO2 hydrogenation to hydrocarbons over heterogeneous catalysts
08:00am - 08:40am USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Society is faced with a CO2 dilemma – we need to slow our production of the gas while simultaneously developing efficient methods to capture, store and/or use it. My group has focused on CO2 capture for over a decade, designing porous materials and processes for CO2 separation from different gas mixtures, including flue gases and ambient air. More recently, we have focused our attention on the conversion of CO2 to useful products, such as hydrocarbons.
In this presentation, I will briefly describe some of the key approaches to CO2 capture, followed by a more detailed description of two approaches for CO2 conversion being explored in my group, (i) a chemical looping pathway based on high temperature CO2 capture coupled with in-situ hydrogenation of the captured CO2 to produce methane or methanol, and (ii) conversion of dilute CO2 into aromatics via a process intensification approach pairing methanol synthesis and zeolite catalysis. The performance of these (i) alkali-promoted supported metal and (ii) mixed metal oxide / zeolite hybrid catalysts will be described.

Sunday
Cesium-promoted ethanol production from CO2 hydrogenation on Cu/ZnO(000) surface: Full mechanistic study
08:40am - 09:00am USA / Canada - Eastern - August 22, 2021 | Room: B218
Dr Xuelong Wang, Presenter, Brookhaven National Laboratory; Pedro Ramírez; Dr Jose A Rodriguez, PhD, Chemistry Department; Ping Liu, Brookhaven National Laboratory
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Efficient conversions of CO2 into value-added chemicals such as alcohols are of great industrial and scientific interest. The Cu/ZnO/Al2O3 catalyst has been extensively studied and commercialized in the industry to produce C1 alcohol, methanol from CO2 hydrogenation. In contrast, for Cu-based catalysts, successful attempts to achieve the production of higher alcohols, such as ethanol, which is safer and offers higher energy density, are very limited, due to the difficulty in C-C bond coupling and thus low selectivity. Most Cu-based catalysts are active for the reverse water gas shift (RWGS) reaction and hydrogenation of CO rather; while the C-O bond activation is difficult, which hinders C-C bond formation. Promoters such as Fe have been reported previously, which can facilitate C-O bond dissociation over Cu catalysts. In addition, alkali metal promoters, including K and Cs, have also shown the capability of C chain growth over Cu-based catalysts. Yet, the reaction mechanism remains elusive.
Here, combining surface science experiments and DFT calculations, we present a detailed mechanistic understanding of the roles that Cs plays in ethanol production at the Cu-Cs-ZnO interface under CO2 hydrogenation condition. Our study not only leads to the discovery of new pathways for ethanol production from CO2 hydrogenation but also opens new possibilities to allow the highly active and selective CO2 conversion to higher alcohols on widely used and low-cost Cu-based catalysts.

Sunday
Development of a zero gap membrane electrode assembly carbon monoxide electrolyzer
09:00am - 09:20am USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Carbon monoxide electroreduction is a rapidly developing field for the production of valuable chemicals. When coupled with CO2 capture and electrochemical conversion, it can be used as a clean CO2 negative process for the production of a variety of products. Carbon monoxide reduction has the distinct advantage over direct electrochemical CO2 reduction to multi-carbon products (C2+) in that it does not suffer from carbonate formation, allowing for higher feed conversion and electrolyte stability. This work focuses on the design and production of a zero gap membrane electrode assembly carbon monoxide electrolyzer which operates at low cell potentials (< 2.5 V) and industrially relevant current densities (> 300 mA/cm2) for the production of acetate and ethylene. Zero gap electrolyzers place the cathode and anode in direct contact with a conductive polymer membrane. This provides distinct advantages over conventionally studied three-compartment flow cell designs, where the cathode is in contact with an aqueous liquid electrolyte. Specifically, the use of a solid polymer membranes increases cell stability while decreasing the electrolyzer internal resistance. We demonstrate the high selectivity of the device for producing acetate and ethylene, achieving high Faradaic efficiencies as well as high molar production rates relative to other C2+ products. The system was also found to have improved current densities and cell voltages when compared to conventional three-compartment carbon monoxide electroreduction systems. The opportunity for products to be shuttled through the membrane, however, leads to a more complicated system when compared to three-compartment systems, where the products are solely captured in the catholyte. An investigation was therefore performed to determine both the anode’s as well as the membrane’s effects on the system’s product output and performance.
Sunday
Withdrawn
09:20am - 09:40am USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person

Sunday
Efficient inteplay of ZrO2 and Ni0 for photocatalytic CO2 conversion into mehtane monitored using 13CO2 and EXAFS
09:40am - 10:00am USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
The reaction mechanism of CO2 photoreduction into methane was elucidated by the time-course monitoring of the mass chromatogram, in situ Fourier transform infrared (FTIR) spectroscopy, and in situ extended X-ray absorption fine structure (EXAFS). Under13CO2, H2, and UV–visible light, 13CH4 was formed at a rate of 0.98 mmol h−1 gcat−1using Ni (10 wt%)–ZrO2 that was effective at 96 kPa. Under UV–visible light irradiation, the 13CO2 exchange reaction and FTIR identified physisorbed/chemisorbed bicarbonate and the reduction because of charge separation in/on ZrO2, followed by the transfer of formate and CO onto the Ni surface (Scheme 1). EXAFS confirmed exclusive presence of Ni0 sites. Then, FTIR spectroscopy detected methyl species on Ni0, which was reversibly heated to 394 K owing to the heat converted from light based on the analysis of Debye-Waller factor changes obtained by EXAFS. Heat reactions were much slower (Figure 1). Using D2O and H2, H/D ratio in the formed methane was in agreement with H/D ratio in reactant. This study paves the way for using first row transition metals for solar fuel generation and on-site fuel supply on planets using only UV–visible light.
<b>Scheme 1.</b> Proposed intermediate species during CO<sub>2</sub> exchange and photocatalytic CO<sub>2</sub> reduction.

Scheme 1. Proposed intermediate species during CO2 exchange and photocatalytic CO2 reduction.

<b>Figure 1. </b>Time course of <sup>13</sup>CH<sub>4</sub> and <sup>12</sup>CH<sub>4</sub> formation during the catalytic test exposed to (A) <sup>13</sup>CO<sub>2</sub> (2.3 kPa), H<sub>2</sub>O (2.3 kPa), and H<sub>2</sub> (21.7 kPa) under UV-visible light and (B) at 393 K, under dark (first 24 h) followed by under UV-visible light (6 h) both using Ni (10 wt%)-ZrO<sub>2</sub>-Reduced (0.020 g).

Figure 1. Time course of 13CH4 and 12CH4 formation during the catalytic test exposed to (A) 13CO2 (2.3 kPa), H2O (2.3 kPa), and H2 (21.7 kPa) under UV-visible light and (B) at 393 K, under dark (first 24 h) followed by under UV-visible light (6 h) both using Ni (10 wt%)-ZrO2-Reduced (0.020 g).


US-Israeli Symposium on C1 Chemistry :
10:30am - 12:00pm USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Aditya Bhan, Organizer, Univ of Minnesota; Oz M Gazit, Organizer, Technion; Prof. Dmitri Gelman, Organizer, The Hebrew University of Jerusalem; Daniel Resasco, Organizer, University of Oklahoma; Aditya Bhan, Presider, Univ of Minnesota
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Division/Committee: [CATL] Division of Catalysis Science & Technology

This symposium explores the topic of C1 conversion in context of the broader chemical enterprise. Presentations will feature research at the state-of-the-art in electrochemical and thermochemical upgrading of C1 species to fuels and chemicals.

Sunday
Effect of surface phase oxides on Ni catalyzed methane dry reforming
10:30am - 11:00am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Anup Tathod; Jin Wang; Oz M Gazit, Presenter, Technion
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Under reducing conditions, a strongly interacting reducible support can hinder the sintering of a nickel (Ni) nano-particle but, may also lead to severely reduced catalyst activity due to overcoating of the Ni by the support (i.e. SMSI). In contrast, Ni supported on a weakly interacting non-reducible support will have lower thermal stability but, can show higher activity. We find that the level of these metal support interactions (MSI) can be balanced using a mediating layer of surface phase thin oxides (SPO) in the form of MgAl mixed oxide nano-platelets (MO). We show that this approach can be practically implemented to balance between the benefits of the strong MSI of the SPO and the weak MSI of the underlying support (SiO2, ZrO2). Testing this approach for methane dry reforming (MDR) we found that the presence of 0.5-2.5 %wt Ni on the SPO, which is dispersed on an underlying ZrO2 surface, enhances the catalytic activity by ~15 fold, as compared to Ni supported on bulk MO. To better understand and control the nature of these interaction we performed extensive HAADF-STEM-EDS and XPS analyses. Planer model catalysts are analyzed using atomic force microscopy (AFM) to study the effect of the underlying support on the Ni and on the exposed surface of the SPO. Obtained information related to surface adhesion, surface potential and surface friction forces of the MO-NSs are correlated to catalyst performance and the mechanism by which the Ni is promoted by the presence of the SPO.
Sunday
Mechanism and surface species for formic acid decomposition on dispersed copper nanoparticles
11:00am - 11:30am USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Mechanistic details of HCOOH dehydrogenation routes on Cu nanoparticles are relevant to C1 chemistries that involve formate-type species as intermediates or spectators, such as water-gas shift and methanol synthesis. It has been widely accepted that HCOOH decomposes unimolecularly on transition metal surfaces via bidentate formate (*HCOO*) intermediate, with its C-H activation kinetically limiting the overall rates. Although such route is relevant during temperature-programmed surface reactions (TPSR) of pre-adsorbed *HCOO* species, bimolecular routes may be prevalent at catalytic conditions when HCOOH(g) coexists with *HCOO*. This study seeks to clarify and update our understanding of HCOOH dehydrogenation routes on Cu nanoparticles by combining kinetic, isotopic, and spectroscopic experiments with density functional theory (DFT) calculations.

At practical conditions (0.1-3.5 kPa HCOOH; 473-503 K), Cu surfaces are covered with *HCOO* species, which reach their saturation at 0.25 monolayer (ML) (*HCOO*/Cusurface=0.25) because of strong repulsion among bound *HCOO* species. HCOOH(g) binds molecularly at the interstices (denoted as ' sites; HCOOH') within such saturated *HCOO* adlayers; such interstices become saturated with HCOOH' upon formation of another 0.25 ML adlayer, with HCOOH' species forming strong H-bonds with vicinal *HCOO*. Measured rates reflect the bimolecular decomposition of the HCOOH'-*HCOO* complex, in which either HCOOH' or *HCOO* can lead to the formation of the CO2 product, while the other one re-forms the *HCOO* adlayer. These two bimolecular routes cannot be distinguished from kinetic data, isotopic effects, or infrared spectra or accessible to TPSR studies. DFT-derived barriers are slightly larger for the route that forms CO2 from HCOOH' than for the one forming CO2 from *HCOO* (ΔHact = 83 vs. 68 kJ mol-1).

These bimolecular routes are consistent with all experimental and theoretical data. This work, in turn, provides a compelling example of how repulsive interactions among bound species restricts their coverages to < 1 ML, thus allowing residual interstices in such “passivated” surfaces to bind intermediates less strongly, thus allowing them to react or to increase the reactivity of the bound species in the more refractory template.

Sunday
Multifunctional pincer complexes possessing a secondary coordination sphere as catalysts for CO2 hydrogenation
11:30am - 12:00pm USA / Canada - Eastern - August 22, 2021 | Room: B216 - B217
Prof. Dmitri Gelman, Presenter, The Hebrew University of Jerusalem
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Hybrid
Burning fossil fuels worldwide has led to an increasing CO2 concentration in the atmosphere to such a large extent that global climate change caused by greenhouse gases has become a major ecological challenge. At present, its amount can be reduced by either capture and storage or by chemical conversion and utilization. There is no doubt that carbon dioxide storage is a cheaper solution and that it is useful for reducing CO2 emissions quickly. Unfortunately, it does not solve the accumulation problem in the long term, whereas converting CO2 into carbon-containing value-added products and feedstock does.
The catalytic conversion of CO2/H2/CO to methanol is already being performed on an industrial scale. Other products, such as formic acid and its derivatives, can be synthesized by carbon dioxide hydrogenation. However, despite this progress, we are still far from the point where carbon dioxide becomes a concrete player in the sustainable chemistry/energy market. Significant steps should be taken toward developing more efficient catalysts for CO2 conversion processes, as well as developing new reaction schemes that allow for more efficient utilization of carbon dioxide in fine and bulk synthesis.
The talk is devoted to designing ligand-metal cooperative catalytic systems for the dehydrogenation of formic acid and hydrogenation of CO2. Our studies revolve around a family of 3-dimensional PC(sp3)P pincer complexes developed by our group. The synthetic approach leading to all these examples is straightforward and represents a modular and divergent approach to a variety of 3-dimensional platforms equipped with custom-tailored primary and secondary coordination spheres. In particular, we address the cooperative activation and functionalization of carbon dioxide by bifunctional catalysts possessing transition metals in the primary coordination sphere and a pendant Lewis acidic functionality in the secondary sphere.

Carbon Capture & Utilization: Conversion of CO2 to Chemicals & Fuels:
10:30am - 12:30pm USA / Canada - Eastern - August 22, 2021 | Room: B218
Juliana Carneiro, Organizer, Georgia Institute of Technology; Kandis Gilliard-AbdulAziz, Organizer, University of California Riverside; Ambarish Kulkarni, Organizer, University of California Davis; Kandis Gilliard-AbdulAziz, Presider, University of California Riverside; Juliana Carneiro, Presider, ‍ ; Ambarish Kulkarni, Presider, University of California Davis
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Division/Committee: [CATL] Division of Catalysis Science & Technology

Carbon Capture and Utilization (CCU) is seen as a means to mitigate the emissions of CO2 with the concomitant use of a catalytic component for the conversion of CO2 to fuels, chemicals and polymers. While research for CO2 capture and utilization can be broad, this symposium will focus on the thermocatalytic and electrocatalytic strategies for CO2 capture and utilization. This symposium will foster the discussion from different perspectives and provide insights to address existing challenges in advancing these technologies further.

Sunday
Nanocrystal-based catalysts for CO2 hydrogenation to fuels and chemicals
10:30am - 10:50am USA / Canada - Eastern - August 22, 2021 | Room: B218
Matteo Cargnello, Presenter, Stanford University; Aisulu Aitbekova; Chengshuang Zhou, Stanford
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
The conversion of CO2 to fuels and chemicals represents an important pathway towards a sustainable future. The reduction of CO2 using renewable hydrogen is heavily researched as one possible avenue. The main challenges associated with this process are the activation of the inert CO2 molecule as well as the control of the selectivity towards specific compounds. Designing catalysts where metal/support interfaces are controlled to exploit their synergy is a viable route to steer the selectivity of the reaction towards desired products such as long-chain hydrocarbons. Furthermore, understanding changes that occur to catalysts under the demanding reaction conditions necessary for CO2 hydrogenation is important to design more efficient materials. In this talk, I will highlight recent work from our group that uses colloidal nanocrystals to prepare well-defined catalysts with inorganic and organic/inorganic hybrid interfaces to control CO2 hydrogenation selectivity. These catalysts demonstrate in some cases specific changes under reaction conditions that lead to modified reactivity and increased production of hydrocarbons following structural rearrangements. In other cases, the specific design of hybrid interfaces allows to obtain materials with much improved selectivity towards desired products, thus highlighting how colloidal nanocrystals can be used to design efficient and selective catalysts for challenging transformations.
Sunday
Theoretical calculations of electrochemical reduction of CO2 to form hydrocarbons and alcohols
10:50am - 11:10am USA / Canada - Eastern - August 22, 2021 | Room: B218
Hannes Jonsson, Presenter, Univ of Iceland Fac SCI Vr II
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
Results of calculations of the electrochemical reduction of CO2 and the competing hydrogen evolution reaction will be presented. Activation energy of the various elementary steps has been evaluated as a function of applied voltage as well as thermodynamic properties. It has been shown experimentally that copper electrodes can give rise to a wide range of products in electrochemical CO2 reduction and a key question is why copper is so special. Many aspects of the experimental measurements can be reproduced nicely by the theoretical calculations. The fact that the onset potential of formate and CO formation is similar can be explained by the fact that the energy barrier for the two competing processes is similar. The rate limiting step for further reduction is the hydrogenation of CO and the calculations show that a Heyrovsky step to form COH is the active mechanism rather than formation of CHO. An understanding of the detailed mechanism is important in order to find ways to improve the selectivity and to reduce the overpotential in order to make electrochemical CO2 reduction viable. Recent studies have, for example, shown that incorporation of CO2 into hydrate clathrates can significantly reduce the overpotential and favor CO2 reduction over hydrogen formation. The rate of C-C bond formation is strongly dependent on the surface structure and can be affected also by addition of small alloying component in the copper electrode. The extension of the simulation methodology to electrochemical reactions is challenging and represents an active front in the development of theoretical tools. Describing the effect of the electrostatic potential on the reaction rate is a challenge, but also the proper inclusion of a liquid dielectric at the surface of the electrode as it makes the DFT calculations too computationally demanding. Various levels of approximations have been developed and compared in the calculations of the electroreduction of CO2.
Sunday
Withdrawn
11:10am - 11:30am USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person

Sunday
Intensified catalytic conversion of CO2 into C1 and C2 chemicals
11:30am - 11:50am USA / Canada - Eastern - August 22, 2021 | Room: B218
Dr. Jesse Thompson, Presenter, University of Kentucky Center for Applied Energy Research; Daniel Moreno; Muthu Kumaran Gnanamani; Pom Kharel; Keemia Abad; Ayokunle Omosebi
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
The use of CO2 produced from power generation plants as a feedstock for creating valuable products offers a commercially viable strategy to reduce greenhouse gas (GHG) emissions and offset the cost of carbon capture. Despite years of CO2 conversion research, the development of efficient, robust, and selective heterogeneous CO2 reduction (CO2R) catalysts to convert CO2 into value-added compounds has yet to fully mature. In recent years, CO2R catalysts have become more sophisticated but still struggle with limited long-term activity. Producing value-added CO2 products via an electrochemical pathway can greatly depend on current density, Faradaic efficiency, electrode material and loading, and performance and material degradation.

To overcome the aforementioned limitations, development of a novel copper-based catalytic electrochemical system that can be used to convert carbon dioxide (CO2) to formic acid has been conducted. Formic acid (FA) is a high-value C1 chemical feedstock, but its current production process can require other high-valued chemicals as inputs, including methanol and/or hydrogen. In order to selectively convert CO2 to FA, Cu-based catalysts are commonly used. The metal-to-oxide interface of these catalysts can be tuned to offer higher peripheral metal-to-oxide interfacial area by alkylamine directed synthesis of morphology controlled metal layers formation on oxides.

The developed process leverages highly conductive mesoporous carbon xerogels electrodes, that have already been demonstrated as excellent supports in fuel cells, with Cu-based catalysts for the electrocatalytic conversion of CO2. Current results indicate that modifying CX cathodes with CuCo:CeO2 produces over 2X increase in FA compared only using Cu or CuCo at an operating voltage of -0.75 V vs. Ag/AgCl. Further FA selectivity customization is available in the -0.75 V to -1.0 V vs. Ag/AgCl range. Additionally, increasing the cell pressure from 1 to 3 bar to take advantage of the greater equilibrium concentration of CO2 increased FA production by over 5X, without compromising the structural integrity of the electrochemical cell.

Sunday
Combined electro-thermochemical system for conversion of waste carbon to C4+ synthetic fuels using 3D-printed reactors
11:50am - 12:10pm USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
With the realization of the global impact of waste carbon on the atmosphere, coupled with a clear and growing demand for abundant electricity, there are both environmental and economic driving forces for capturing and converting carbon dioxide (CO2) into high value hydrocarbon products. Two conversion approaches that have been studied extensively are the electrochemical CO2 reduction reaction (eCO2R) and the thermochemical Fischer-Tropsch reaction (F-T); however, leveraging the two reactions together for direct CO2 conversion to synthetic fuels has been challenging due to mismatched reactor size and scales of production, incompatible operating conditions, and poor stability of F-T catalysis in the presence of CO2-rich reactant streams.

This work employs advanced manufacturing to bridge the gap between these two technologies by creating custom 3D-printed reactors. These reactors were designed to align the scale of production for each reaction and consequently allow for a combined electrochemical-thermochemical approach for converting CO2 to C4+ synthetic fuels. A range of operating conditions for each process were investigated: for eCO2R, electrochemical potential and reactor geometry were tailored for maximum conversion of CO2 to CO and optimal ratio of H2:CO; for F-T, catalyst synthesis and operating temperature were studied for conversion of CO2-rich reactant streams to multi-carbon products at ambient pressure. As a result, we report a joint electro-thermochemical system that reaches a maximum of 20% single-pass conversion of CO2 that is stable for over 8 hours; furthermore, we achieve > 60% selectivity to C4+ products. This work represents a method to achieve high selectivity to desired products from CO2, as well as a viable path for scaling these technologies together for sustainable production of synthetic fuels and valuable products from waste carbon.

Sunday
Life cycle assessment of an integrated direct air capture system with advanced algal biofuel production
12:10pm - 12:30pm USA / Canada - Eastern - August 22, 2021 | Room: B218
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - In-person
This study investigates the life cycle environmental impacts of options for integrating a solid amine-based DAC system with advanced algal biofuel production in photobioreactors (PBRs). DAC utilization allows the removal of atmospheric CO2 while also decoupling algae production facilities from anthropogenic point CO2 sources and avoiding the challenges of transporting CO2 long distances to remote facilities. Life cycle assessment is used to assess the environmental benefits of heat and mass integration between the DAC and the PBR for biofuel production. The analysis includes life cycle greenhouse gas emissions, water consumption, land use, criteria air pollutant emissions, and wastewater emissions. This presentation will discuss a range of options and will evaluate the potential for low carbon, sustainable biofuel through air capture of carbon dioxide.
Multiscale Modeling in Heterogeneous Catalysis:
10:30am - 12:30pm USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
fanglin che, Organizer, University of Massachusetts Lowell; Alexander Mironenko, Organizer, University of Illinois at Urbana-Champaign; Alexander Mironenko, Presider, University of Illinois at Urbana-Champaign; fanglin che, Presider, University of Massachusetts Lowell
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Division/Committee: [CATL] Division of Catalysis Science & Technology

In silico design of novel catalytic materials hinges on the availability of accurate and representative multiscale models of complex catalytic phenomena. By providing a link between first-principles estimates of elementary thermodynamic and kinetic parameters and the macroscopic reactor behavior, such models hold promise to bridge pressure and material gaps in heterogeneous catalysis and thereby enable experimentally testable predictions. This symposium will promote exchange of ideas and knowledge on methodology and applications of multiscale models in heterogeneous catalysis.

Sunday
AI-enabled prediction of subnanometer catalyst stability and dynamics
10:30am - 10:50am USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Dionisios Vlachos, Presenter
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Observing catalysts under reaction conditions is generally difficult. Several spectroscopic methods are performed in situ rather than operando. As a result, there is strong debate about the catalyst stability. Computational methods can provide insights into the catalyst stability and dynamics but are typically plagued by the multiscale nature of phenomena and the complex and combinatorial number of the structures of catalysts. In this talk we present an AI-enabled multiscale framework to understand the stability and dynamics of subnanometer catalysts.
Sunday
Distributed parallelisation of kinetic Monte-Carlo simulations for heterogeneous catalysis with the time-warp algorithm
10:50am - 11:10am USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Kinetic Monte-Carlo (KMC) simulations have been instrumental in multiscale catalysis studies by elucidating the complex dynamics of heterogeneous catalysts and translating nanoscale reactive events to macroscopic performance metrics, such as activity and selectivity. However, the accessible length- and time-scales are still limited. In fact, handling lattices containing millions of sites with “traditional” sequential KMC implementations becomes challenging due to the large memory requirements and the heavy computational demand.
On the other hand, parallelisation approaches based on domain decomposition techniques are quite challenging to implement in KMC simulation due to the inherently sequential nature thereof, by which one reactive event is causally linked to future (and past) events. These causal relations, in combination with the random time advancement in each KMC step, necessitate sophisticated protocols for conflict resolution at the boundaries between subdomains. The so-called Time-Warp algorithm offers a way towards addressing this challenge with local operations: sending and receiving messages and anti-messages (the latter encoding “undo” actions), saving snapshots of the simulation state, as well as rolling-back in time and reinstating a previous state. Thus, any causality violations, arising transiently during simulation, are corrected, and the exact dynamics of the underlying stochastic model (the master equation) are faithfully reproduced.
In this work, we have coupled the Time-Warp algorithm with the Graph-Theoretical KMC framework making it possible to handle complex adsorbate lateral interactions and reaction events within very large lattices. This approach has been implemented in Zacros, our general-purpose KMC software, and been validated and benchmarked for efficiency in model systems as well as realistic chemistries. This work makes Zacros the first-of-its-kind general-purpose KMC code with distributed parallelisation capability to study heterogeneous catalysts.

Sunday
MD simulations with chemical accuracy: Alkane reactivity in acidic zeolites
11:10am - 11:30am USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Fabian Berger, Presenter, Humboldt University of Berlin; Marcin Rybicki; Joachim Sauer
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Adsorption is a fundamental step in heterogeneous catalysis that strongly affects the reaction kinetics and diffusion within the catalyst, but inherently poses a multiscale problem. While the dynamic behavior of adsorbates can only be properly described by approaches that sample for long times, e.g. Molecular Dynamics (MD) simulations, a chemically accurate description of explicit adsorbate-host interactions requires methods beyond density functional theory (DFT).
The standard approach to calculate adsorption enthalpies considers only the energetically most stable structure (“static” approach) on the potential energy surface (PES) and is based on DFT augmented with dispersion terms (DFT-D). It is currently almost exclusively used, despite its shortcomings: (i) semi-empirical description dispersion, (ii) self-interaction correction errors when performed with GGA functionals, (iii) improper sampling of the configurational space, and (iv) harmonic partition functions.
While adsorption enthalpies calculated via the standard approach largely deviate from experiments, MD simulations at the DFT-D level account for finite temperature effects but are still far from reaching chemical accuracy. To approach chemical accuracy, post-Hartree-Fock methods, e.g. MP2, are required, but limited to a small number of calculations which are not sufficient to get converged enthalpies.
We introduce a combined hybrid MP2:PBE+D2 MD approach that overcomes the problems of standard DFT-D calculations. While the sampling of the configurational space is computed with MDs at the PBE+D2 level, the enthalpies are based on fitted MP2:PBE+D2 energy surfaces. MP2 corrections to the adsorption enthalpy are only calculated for selected snapshots and used to parametrize a 2-dimensional linear model of physically motivated structure parameters. This model is used to calculate MP2 corrections for each step of the MD, effectively reducing the computation time for a “MP2-quality” MD of 100,000 steps from about 340 years to 3 weeks. We illustrate the accuracy and robustness of this approach by calculating alkane adsorption enthalpies in different zeolites, at varying temperatures, and Brønsted acid site densities. For all investigated systems, chemically accurate adsorption enthalpies have been obtained. Furthermore, the adsorption enthalpies have been used to obtained intrinsic reaction barriers for alkane cracking in H-MFI with unprecedented accuracy, improving rate constants by a factor of 50.

Sunday
Understanding the role of solvent effects in the thermal and electrochemical hydrogenation of organics
11:30am - 11:50am USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Contrary to solid/gas interfaces, in solid/liquid interfaces the molecules in the liquid can be organized such that those near the surface are appreciably different from the bulk. This can be impacted by: the composition of the liquid phase, the size shape and loading of nanoparticles and the hydro/lipophilicity of the support. In this talk. we will outline the findings from our ongoing studies of both thermal and electrochemically driven hydrogenation of organic molecules. We will present both classical and ab into molecular dynamics calculations that simulate the structure and composition within the double both at the support as well as on surface of catalytic nanoparticles. The calculations explicitly identify the different roles of entropy and binding energy on the activity and selectivity of solution phase hydrogenation. A first example shows how H2 adsorption on Pt(111) becomes appreciably weaker in the presence of water as compares with vapor phase. phenol/water mixtures behave on hydrophilic and lipophilic surfaces and provides a possible explanation as to why a higher phenol hydrogenation conversion is observed on Pd catalysts on hydrophilic surfaces than on lipophilic surfaces. We show how reaction rates can be manipulated by changing the concentration of phenol adjacent to the catalysts through modification of the degree of support hydrophilicity, size and loading of nanoparticles, and temperature. We also discuss the role of water in changing the adsorption free energetics on Pt surface. In a final example, we simulate the speciation on metal and/or graphitic carbon cathodes of a complex solvent mixture containing organics, salts, acids, as a function of cathode charge and temperature. Here we show that the ability to transfer an electron to the organic is governed by the amount of organic in the double layer as well as its orientation with respect to the electrode surface.

Sunday
Selective methane to methanol converion on metal oxide catalysts
11:50am - 12:10pm USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Erwei Huang, Stony Brook University; Ping Liu, Presenter, Brookhaven National Laboratory
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
The development of variable catalysts to promote the methane activation and control the conversion selectivity has long been a challenge in catalysis. One of the obstacles is the lacking in fundamental understanding of reaction network due to the complexity. Here, the selective oxidation of methane by oxygen and/or water to methanol will be presented using combined Density Functional Theory and kinetic Monte Carlo simulation. Our results not only provide new insight into the mechanism and active sites, but also highlight the importance of choice of oxidizing agent in tuning the catalytic selectivity.
Sunday
Discovering terpene catalysis inside nano-capsules with multiscale modeling and experiments
12:10pm - 12:30pm USA / Canada - Eastern - August 22, 2021 | Room: Zoom Room 25
Shani Zev; Efrat Pahima; Prof. Dan Major, Presenter, Bar Ilan University
Division: [CATL] Division of Catalysis Science & Technology
Session Type: Oral - Virtual
Large-scale production of natural products, such as terpenes, presents a significant scientific and technological challenge. One promising approach to tackle this problem is chemical synthesis inside nano-capsules, although enzyme-like control of such chemistry has not yet been achieved. In order to better understand the complex chemistry inside nano-capsules, we design a multiscale nano-reactor simulation approach. The nano-reactor simulation protocol consists of hybrid quantum mechanics-molecular mechanics-based high temperature Langevin molecular dynamics simulations. Using this approach we model the tail-to-head formation of monoterpene and sesquiterpenes inside a resorcin[4]arene-based capsule (capsule I). We provide a rationale for the experimentally observed kinetics of terpene product formation and product distribution using capsule I. Based on the in-capsule I simulations, and mechanistic insights, we propose that one can also predict product distributions inside the capsule.