Insights into electrochemical CO2 reduction on tin oxides from first-principles calculations

• DOI: 10.1016/j.gee.2017.02.005
• Publication Date: 2017-03-07T18:03:40Z
• Authors: Siwen Wang; Jiamin Wang; Hongliang Xin
• Keywords: Reactivity

Density functional theory calculations were used to unravel the mechanism of CO2 electroreduction on SnOx surfaces. Under highly reducing conditions (< −0.6 V vs. RHE), SnO(101) surface with oxygen vacancies is likely active phase for reduction. We showed that proton-electron transfer adsorbed *CO2 forming *OCHO, a key intermediate producing HCOOH, energetically more favorable than formation *COOH, justifying selectivity trends observed Sn-based electrocatalysts. With linear scaling relations, we propose free energy at vacancy as reactivity descriptor. By engineering strain surface, towards HCOOH can be further optimized reduced overpotentials.