(43a) Computational Study on Electrochemical Reduction of CO2Â using Transition Metal- p Block Catalyst Compositions
We performed plane wave DFT calculations on VASP 5.4x installed in the Materials Design MEDEA environment to calculate electronic structure properties. Throughout this work, all the electronic structure calculations are performed using Van Der Waals, opt âPBE functional. A Fermi smearing of 0.2 eV is used and calculations are performed with gamma centered k-points mesh of 2x2x1 with convergence of ground state energies less than 0.05eV/mole-unit cell with respect to k-point sampling. A vacuum space of 12 Ã is defined to minimize the interactions between repeated slabs.
In this work, we investigated the catalyst activity and product selectivity of various transition metal oxide and sulfide catalysts for the CO2 reduction reaction. We predicted the lowest energy pathway for CH3OH and CH4 formation from free energy diagrams (FEDs) and computed their corresponding reducing potentials and overpotentials . We inferred that both methane and methanol share common intermediate species in their mechanisms and these species either bind through carbon atom (via CO) or oxygen atom (via OH). Therefore, we developed scaling relations between all the active C bound intermediate species with ð¥G (CO*) and O bound intermediate species with ð¥G (OH*) to determine and rank the activity of different catalyst materials. We built thermodynamic volcano plots using these scaling relations which could further benefit in capturing the activity trends in CO2RR using transition metal/p-block catalyst materials. In this presentation, we will also show how electronic and geometric changes would affect catalyst activity and product selectivity for CO2 electroreduction process which could help in designing/developing an ideal catalyst for CO2RR in the near future.