The present CO₂ level in the atmosphere is > 410 ppm, endangering human fauna and habitats. The four Rs (Reduce, Reuse, Recycle, and Remove) are environmental measures for lowering CO₂ emissions. Herein, we developed an electrocatslyst to reuse the CO₂ for fuel formation via electrochemical CO₂ reduction reaction (CO₂RR). In this study, we synthesized a bimettalic indium-tin metal-organic framework (MOF) by solvothermally combining benzene dicarboxylic acid (bdc), 2.0% Indium (In), and 98% Tin (Sn) at 60 °C. The resulting catalysts were characterized by XRD, SEM, EDX, BET and FTIR. The In-Sn MOF exhibit identical crystalline peaks in the XRD to those of the stimulated Sn-MOF. The SEM reveals that the predominate cuboid shape of Sn-MOF is a typical spherical shape. The EDS offers 1.8 wt.% loading into the Tin-MOF, which is less than the theoretical add value (2.0 wt.%). Using a catalyst ink dissolved in isopropanol on carbon paper, a functional electrode was prepared on conductive carbon paper. The prepared electrode used in H-Cell for CO₂RR. The LSV, CV and EIS of In-Sn-MOF shows higher current density and higher conductivity compare to the prestine Sn-MOF. The electrocatalyst was further evaluated for CO₂RR at constant potential using an Ag/AgCl electrode with an aqueous 0.1 M KHCO₃ electrolyte. Water suppression NMR analysis of the liquid product revealed only formic acid. The quanitittvie results revealed the formation of formic acid with the highest Faradic Effeciency (FE) of 70 % at -1.1 vs RHE and a higher partial current density compare to the prestine Sn-MOF. We believe this catalyst has the potential to produce formic acid from CO₂ by an economically viable method.

Figure a) XRD of Sn-MOF and In-Sn-MOF, b)SEM of In-Sn-MOF c)EDX of In-Sn-SEM, d) BET of of Sn-MOF and In-Sn-MOF, e) CV of In-Sn-MOF, f) FE of In-Sn-MOF.

Bader Alghamdi

Appearances