Towards efficient CO2RR electrocatalysts: a study of structure and properties of M–N–E active moieties embedded in a biphenylene framework (M = Mn, Fe, Co, Ni, Cu; E = C, B)

Abstract

In the context of C-based 2D nanomaterials, the stereoelectronic situation of putative M–N–E active moieties (M = Mn, Fe, Co, Ni, Cu; E = C, B) embedded in biphenylene (BPN) monolayer frameworks and their electrocatalytic performance in the CO₂ greenhouse gas reduction reaction (CO₂RR) are studied in silico by means of dispersion-corrected DFT, AIMD, CI-NEB, and COHP quantum chemical calculations. It is found that the M–N–B-modified BPN framework possesses excellent thermal and electrochemical stability, capability for effective localization of the solid-state electron-energy bands originated from the d-AOs of M atoms, and enhanced affinity towards the CO₂RR intermediates, which reduces the Gibbs free energy and facilitates the CO₂RR. The Fe–N–B active moiety exhibits excellent adsorption performance for CO₂RR intermediates through secondary bonding interactions, as well as selectivity towards CH₃OH and CH₄ high-value production revealing the limiting potential U_L = 0.64 V in both cases, while the Co–N–C moiety reveals the optimal U_L of 0.6 V favoring the CO₂RR both kinetically and thermodynamically. Importantly, the M–N–E active moieties prevent the CO₂RR-competing hydrogen evolution reaction (HER). Overall, M–N–E-modified BPN frameworks are promising for the design and synthesis of novel efficient CO₂RR electrocatalysts.