CO₂ conversion and utilization for global sustainability is an integral part of greenhouse gases management, typically for the production of fuels and specialty chemicals. The main motivation of this study is to develop a copper based catalyst active in both electrocatalysis and thermocatalysis, confronting the main concerns regarding typical metal catalysts related to nanoparticles aggregation and deactivation. For this, modified NU-1000, a water-stable mesoporous MOF, is used as a platform for the simultaneous coordination-stabilization of copper single atoms and CO₂ adsorption. NU-1000 is synthetized with primary amino groups (-NH₂ with affinity for CO₂) by modifying the ligand prior to MOF synthesis, while post-synthetic solvent-assisted ligand incorporation is applied to insert thiol functionalities (-SH with affinity for copper) within the framework. To make the functionalized MOF catalytically active, a Cu²⁺ salt is impregnated into the MOF channels, which is further reduced with H₂ to Cu⁺/Cu⁰ before performance assessment in CO₂ conversion processes (Fig. 1) [2]. The electrocatalytic reduction of CO₂ indicated the formation of formic acid, while thermocatalytic hydrogenation was 100% selective towards methanol formation with a space-time yield of ca. 100 mg_MeOHg_cat^-1h^-1 which overcomes that of commercial CuZnO NPs designed for this purpose (Fig 2).

<b>Fig. 1 </b>Schematic representation of the followed steps to synthesize NU-1000-NH<sub>2</sub>/PrSH-Cu.

Fig. 1 Schematic representation of the followed steps to synthesize NU-1000-NH₂/PrSH-Cu.

<b>Fig. 2</b> MeOH space-time yield (STY) and MeOH selectivity (S<sub>CH3OH</sub>) of NU-1000-NH<sub>2</sub>/PrS-Cu compared to commercial CuZnO/Al<sub>2</sub>O<sub>3</sub> at different temperatures.

Fig. 2 MeOH space-time yield (STY) and MeOH selectivity (S_CH3OH) of NU-1000-NH₂/PrS-Cu compared to commercial CuZnO/Al₂O₃ at different temperatures.

Leila Negahdar

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