Nanoporous structured Sn‐MWCNT/Cu electrodes fabricated by electrodeposition–chemical dezincification for catalytic CO₂ reduction

Abstract

A facile method is developed to fabricate nanoporous, structured, Sn-based catalyst electrodes. Sn, Zn, and multiwalled carbon nanotubes (MWCNTs) are coelectrodeposited on a copper substrate, followed by chemical dezincification in NaOH aqueous solution to remove Zn. By controlling variables such as the contents of Zn and MWCNTs, a series of Sn-MWCNT/Cu (S Z MC) electrodes are fabricated. Experimental results show that using such novel S Z MC electrodes can achieve a HCOO − Faradaic efficiency of over 91% at −0.99 V versus RHE for 10 hours in CO 2-saturated 0.5 M KHCO 3 aqueous solution. The high performance is attributed to the addition of MWCNTs and Zn, followed by chemical dezincification to remove Zn and then create vacancies in the catalyst structure, which results in a special porous structure of S Z MC with large surface area. Then ECSA is used for enhancing the catalytic activity and selectivity of HCOO − production, as well as promoting intermediate adsorption and mass transfer.

ZnSn nanocatalyst: Ultra-high formate selectivity from CO2 electrochemical reduction and the structure evolution effect

“…Electrochemical CO 2 reduction reaction (eCO 2 RR) is attractive to close the carbon cycle by consuming CO 2 and providing CO, H 2 , hydrocarbon and other chemical products [1][2][3][4][5][6]. Until now, many efforts have been made to promote the activity and selectivity of eCO 2 RR, including size and morphology engineering [7][8][9][10], grain boundary construction [11], crystal face optimization [12,13] and composite fabrication of relative catalysts [14][15][16][17][18]. However, the selectivity of eCO 2 RR is still a challenge because of the similar thermodynamic potentials of the reduction products and competing hydrogen evolution reaction (HER) [19].…”