Au aerogel for selective CO2electroreduction to CO: ultrafast preparation with high performance

Shenglin Yan; Samah A Mahyoub; Jing Lin; Chunxiao Zhang; Qing Hu; Chengzhen Chen; Fanghua Zhang; Zhenmin Cheng

doi:10.1088/1361-6528/ac4287

Au aerogel for selective CO₂electroreduction to CO: ultrafast preparation with high performance

Nanotechnology. 2021 Dec 28;33(12). doi: 10.1088/1361-6528/ac4287.

Authors

Shenglin Yan¹, Samah A Mahyoub¹, Jing Lin¹, Chunxiao Zhang¹, Qing Hu¹, Chengzhen Chen¹, Fanghua Zhang¹, Zhenmin Cheng¹

Affiliation

¹ State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.

PMID: 34902843
DOI: 10.1088/1361-6528/ac4287

Abstract

Noble metal aerogels (NMAs) have been used in a variety of (photo-)electrocatalytic reactions, but pure Au aerogel (AG) has not been used in CO₂electroreduction to date. To explore the potential application in this direction, AG was prepared to be used as the cathode in CO₂electroreduction to CO. However, the gelation time of NMAs is usually very long, up to several weeks. Here, an excess NaBH₄and turbulence mixing-promoted gelation approach was developed by introducing magnetic stirring as an external force field, which therefore greatly shortened the formation time of Au gels to several seconds. The AG-3 (AG with Au loading of 0.003 g) exhibited a high CO Faradaic efficiency (FE) of 95.6% at an extremely low overpotential of 0.39 V, and over 91% of CO FE was reached in a wide window of -0.4 to -0.7 V versus the reversible hydrogen electrode (RHE). Partial current density in CO was measured to be -19.35 mA cm^-2at -0.8 V versus RHE under 1 atm of CO₂. The excellent performance should be ascribed to its porous structure, abundant active sites, and large electrochemical active surface area. It provides a new method for preparation of AG with ultrafast gelation time and large production at room temperature, and the resulting pure AG was for the first time used in the field of CO₂electroreduction.

Keywords: Au aerogel; CO; CO2 electroreduction; cathode; turbulence mixing.