Computational evaluation of CO conversion into formic acid via a novel adsorption mechanism on metal-free BC.

The electrochemical reduction of CO (CO2RR) to formic acid (HCOOH) is a promising approach to harness renewable energy for the production of value-added chemicals and contribute to carbon cycling. The search for cost-effective and efficient metal-free electrocatalysts is critical for realizing industrial applications. However, limited literature is available on this topic, primarily because the significant challenge of efficiently activating inert CO remains unresolved. In this study, we have designed and applied a novel boron carbide (BC) monolayered cage as an electrocatalyst for CO2RR to produce HCOOH. BC exhibits exceptional electronic, dynamic, and thermodynamic stability. Through comprehensive density functional theory computations, we have observed that BC rapidly and stably adsorbs CO in a unique η(O, C, O)-CO configuration, resulting in excellent CO2RR activity with a low limiting potential (-0.38 V) and suppressed hydrogen evolution reaction. Our mechanistic investigations reveal that BC donates electrons to facilitate the bending of CO, anchoring it onto the curved surface effectively. Additionally, the C atom in the η(O, C, O)-CO configuration attracts H + e pairs through its active p electron, leading to the observed low limiting potential. This study not only successfully designs a novel class of metal-free electrocatalysts but also provides a promising strategy for advancing CO2RR research in the future.