Pristine and transition metal doped 2D AlSb as high performance electrocatalyst for selective CO2 reduction: A first-principles study

Abstract

Electrochemical CO2 reduction reaction (CO2RR) using 2D nanomaterials has emerged as a sophisticated approach to mitigate industrial CO2 emissions. In this work, the potential application of pristine as well as strategically Fe, Co, Ni-doped 2D AlSb was examined as a CO2RR electrocatalyst. The recation pathways of CO2RR intermediate complexes, overpotential, stability, efficiency, and selectivity were studied using density functional theory (DFT). Outstanding overpotentials were achieved with pristine and doped 2D AlSb: Ni-doped 2D AlSb was selective for HCOOH (0.12eV) and CH4 (0.28eV), and Fe-doped 2D AlSb for HCHO (0.31eV) and CH3OH (0.31eV). The opposing effects of hydrogen evolution reaction (HER) was mitigated with the application of electric potential and solution pH. The main reasons for the enhancement of catalytic effect due to doping with Fe, Co, and Ni are bandgap reduction and creation of states at the edge of the valence band due to the 3d orbitals of these dopants. Interestingly, the Fe-doped 2D AlSb catalyst exhibited the highest catalytic activity. Excellent electrocatalytic properties of pristine and doped 2D AlSb make them suitable as CO2RR catalysts contributing towards a green and sustainable energy ecosystem.