Electrochemical reduction of CO₂ to formic acid using novel 2D catalysts

Abstract

Electrochemical CO₂ reduction has been a widely explored process to convert CO₂ into valuable chemicals and fuels, promoting sustainable living by reducing the global carbon footprint. In this reduction process, nanostructured two-dimensional (2D) materials have demonstrated promising performance as electrocatalysts for CO₂ reduction. In this report, a comparative study of how four different 2D materials with carbon support affect this reaction is shown. The tested materials were AgInP₂S₆, Bi₂SeTe₂, Sb₂Se₃ and Sb2₂S₃ while the carbon support selected was carbon black. Bi₂SeTe₂ was found to have the most promising performance as it has the highest selectivity of formic acid with faradaic efficiencies (FEs) ranging between 50.9% to 60.9% at all potential values applied. AgInP₂S₆ also showed generally moderate selectivity of formic acid formation with FEs ranging from 20.0% to 34.0%. In addition, Sb₂S₃ was found to give relatively significant FE of 34.0% at an applied potential of -1.26 V despite its low selectivity of formic acid at lower potentials. Further study was conducted to examine the nanostructures and elemental compositions of the 2D materials to better understand their electrochemical CO₂ reduction performance.