Bismuth Metal-Organic Framework Based Catalyst for CO2 Electroreduction

Abstract

Electrochemical reduction of CO2 into different fuels and other valuable chemicals is a highly promising method of CO2 valorisation. Among the many possible compounds that CO2 can be reduced to, formic acid is especially attractive because it already has quite a large market in agriculture and the pharmaceutical industry. It can be used directly in a formic acid fuel cell or as hydrogen storage for hydrogen fuel cells. The catalysts used for this reduction process need to strongly absorb CO2 and show poor activity towards the hydrogen evolution reaction (HER) so that it would not interfere. This work focuses on Bi-N-C electrocatalysts fabricated by carbonization of TAL33 MOF compounds at different temperatures. The electrochemical activity of the catalysts was measured, and some samples showed Faradaic efficiencies up to 100 % and formed formic acid at concentrations up to 20 mM after 90 minutes. To investigate why samples at different carbonization temperatures showed different results, surface morphological studies were conducted. Results obtained in electrochemical experiments were further confirmed by theoretical calculations.