Modulating Activity through Defect Engineering of Tin Oxides for Electrochemical CO(2) Reduction

The large‐scale application of electrochemical reduction of CO(2), as a viable strategy to mitigate the effects of anthropogenic climate change, is hindered by the lack of active and cost‐effective electrocatalysts that can be generated in bulk. To this end, SnO(2) nanoparticles that are prepared using the industrially adopted flame spray pyrolysis (FSP) technique as active catalysts are reported for the conversion of CO(2) to formate (HCOO(−)), exhibiting a FE(HCOO) (−) of 85% with a current density of −23.7 mA cm(−2) at an applied potential of −1.1 V versus reversible hydrogen electrode. Through tuning of the flame synthesis conditions, the amount of oxygen hole center (OHC; Sn≡O●) is synthetically manipulated, which plays a vital role in CO(2) activation and thereby governing the high activity displayed by the FSP‐SnO(2) catalysts for formate production. The controlled generation of defects through a simple, scalable fabrication technique presents an ideal approach for rationally designing active CO(2) reduction reactions catalysts.