Highly efficient electroreduction of CO2 to formate by nanorod@2D nanosheets SnO

Electrochemical carbon dioxide reduction reaction (CO2RR) is a key to achieving practical renewable energy conversion and storage as well as green chemical productions. Sn-based electrocatalysts are believed to be one of the most promising candidates for the electroreduction of CO2 to formate. However, development of novel catalysts operating at low overpotentials with a high selectivity, large current density and high single-pass conversion of CO2 (SPC) simultaneously remains a significant challenge. Here, we report a [email protected] SnO (NRS-SnO) catalysts designed with abundant exposed Sn(II) active sites in the 2D nanosheets for high-performance electroreduction of CO2 to formate. Formate was first reliably detected at an applied potential as low as −0.2 V (vs. RHE) and reached maximum Faradaic Efficiency (FE) of ca. 94 % at −0.7 V (vs. RHE) with a partial current density (JHCOO-) of ca. −330 mA/cm2, giving the highest cathodic CO2-to-formate energy conversion efficiency (ca. 70 %) among known Sn catalysts for CO2RR to formate. Importantly, a high SPC of 39.3 % was achieved with the present system, proving for the first time that high SPC can be achieved for GDE based alkaline flow cell.