A low crystallinity CuO-SnO2/C catalyst for efficient electrocatalytic reduction of CO2

Abstract

Electrochemical method to convert CO2 into valuable industrial fuel or raw material is an important means to establish a new carbon cycle. However, low selectivity and poor stability of electrocatalysts seriously limited its potential application. In this paper, by the efficient integration of CuO and SnO2 on carbon black (C), a low crystallinity CuO-SnO2/C catalyst was synthesized, which exhibited drastically enhanced selectivity, activity and stability towards carbon dioxide reduction reaction (CO2RR). It is found that CuO and SnO2 nanoparticles are well distributed on carbon black carrier, resulting in larger value of the electrochemically active surface area (ECSA) and faster electron transfer capacity, which contributes to the enhanced electrocatalytic process. Especially, the obviously lower crystallinity of CuO on CuO-SnO2/C is in favor of the easier transfer of electron to CO2 surface to form the intermediate CO2·-, accelerating the reduction reaction. Therefore, as-obtained CuO-SnO2/C with low crystallinity efficiently catalyzes the reduction of CO2 to formic acid and syngas in a facile process, with the highest Faradaic efficiency (FE) of C1 products (HCOOH + CO) of 80 %, and 100 % FE can be utilized. The findings here present a novel way for crystallinity tuning of a material to efficiently manipulate its electrocatalytic properties towards CO2RR.