Electrodeposition of CuxBi1-x-MOF for electrochemical reduction of CO2

Electrochemical reduction of carbon dioxide to hydrocarbon compounds such as formate offers a promising pathway to carbon-neutral future. Bismuth (Bi) has the advantages of low toxicity, good economic returns, and high overpotentials for hydrogen evolution reaction (HER). However, the Faradic efficiencies and yield rates of Bi-based catalysts still need to be improved before applying to practical applications. In this work, bimetallic metal–organic framework Cux/Bi1-x-BTC was loaded on a copper foam electrode by one-step electrodeposition to form a catalytic electrode. The performance of Cux/Bi1-x-BTC electrodes for reducing carbon dioxide to formic acid was evaluated in H-type electrolytic cells. Electrochemical-prepared Cux/Bi1-x-BTC showed higher reaction rate and Faraday efficiency (FE). than either Cu-BTC or Bi-BTC in CO2‒saturated 0.1 M KHCO3 solution. Carbon dioxide was reduced to formic acid on CuxBi1-x-BTC electrtode. The Faradaic efficiency reached 73.4% at −1.5 V (vs. Ag/AgCl) and the conversion rate was 2.68×10−4 mol h−1 cm−2.