Computational Investigation of Hydriding and Strain Effects on theBinding Energies of Electrochemical CO2RR and HER Intermediates

초록

A two-step process, involving syngas production, has recently beensuggested as a feasible strategy for resolving the limit to the selectivity that can beachieved by fuel production via the electrochemical carbon dioxide reduction reaction(CO2RR). In pursuit offinding the optimal phase, orientation, and strain conditions ofa Pd substrate for syngas production, we investigate the effects of hydriding and strainon the binding energies (BEs) of CO2RR and hydrogen evolution reactionintermediates on the (111), (100), and (110) surfaces of Pd by using densityfunctional theory calculations. The calculation results show that the BEs are weakenedby hydriding, most significantly on the (111) surface, rendering it more energeticallyfavorable for syngas production than the others at sufficiently negative potentials. It isalso shown that PdH(100) can be more energetically favorable than PdH(111) undercompressive strains at weakly negative potentials owing to the high strainsusceptibilities of the*CO BEs on the surface. These results are explained in termsof the effects of hydriding and strain on the electronic structures of Pd surface atoms and adsorption-induced mechanicalinteractions.

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