Computational design of bimetallic Tm_(2)@g-C_(9)N_(4)electrocatalysts for enhanced CO reduction toward C_(2)products

Electrochemical CO reduction(ECOR)as a potential strategy for producing valuable chemicals and fuels has captured substantial attention.However,the currently available electrocatalysts suffer from poor selectivity and low Faradaic efficiency,limiting their industrial application.Herein,we systematically investigate the potential of homonuclear bimetallic electrocatalysts,Tm_(2)@C_(9)N_(4)(TM=Fe,Co,Ni,and Cu),for the ECOR through extensive density functional theory calculations.Our findings suggest that all four proposed monolayers exhibit exceptional stability,making them highly suitable for experimental synthesis and practical applications.Interestingly,these transition-metal dual atoms anchored on C_(9)N_(4)monolayers show great potential in facilitating the production of high-value C_(2)products,such as C_(2)H_(5)OH and C_(2)H_(4),due to the significantly low limiting potentials(-0.06~-0.46 V)and small kinetic energy barriers(0.54–1.08 eV)for the CO coupling process.Moreover,with the exception of Ni_(2)@C_(9)N_(4),these bimetallic catalysts demonstrate the impressive suppression of the competitive hydrogen evolution reaction(HER),leading to a high selectivity for C_(2)products in ECOR.Our predictions would accelerate the development of high-performance C_(9)N_(4)-based dual-atom catalysts for the ECOR.

Computational prediction of Mo_(2)@g-C_(6)N_(6) monolayer as an efficient electrocatalyst for N_(2) reduction

Electrocatalytic nitrogen reduction reaction(NRR)is an environmentally friendly method for sustainable ammonia synthesis under ambient conditions.Searching for efficient NRR electrocatalysts with high activity and selectivity is currently urgent but remains great challenge.Herein,we systematically investigate the NRR catalytic activities of single and double transition metal atoms(TM=Fe,Co,Ni and Mo)anchored on g-C_(6)N_(6) monolayers by performing first-principles calculation.Based on the stability,activity,and selectivity analysis,Mo_(2)@g-C_(6)N_(6) monolayer is screened out as the most promising candidate for NRR.Further exploration of the reaction mechanism demonstrates that the Mo dimer anchored on g-C_(6)N_(6) can sufficiently activate and efficiently reduce the inert nitrogen molecule to ammonia through a preferred distal pathway with a particularly low limiting potential of -0.06 V.In addition,we find that Mo_(2)@g-C_(6)N_(6) has excellent NRR selectivity over the competing hydrogen evolution reaction,with the Faradaic efficiency being 100%.Our work not only predicts a kind of ideal NRR electrocatalyst but also encouraging more experimental and theoretical efforts to develop novel double-atom catalysts(DACs)for NRR.