Critically, the central metal atoms along with their coordination environment play a significant role in the catalytic performance of single-atom catalysts (SACs). Herein, 12 single Fe, Mo, and Ru atoms supported on defective graphene are theoretically deigned for investigation of their structural and electronic properties and catalytic nitrogen reduction reaction (NRR) performance using first-principles calculations. Our results reveal that graphene with vacancies can be an ideal anchoring site for stabilizing isolated metal atoms owing to the strong metal−support interaction, forming stable TMC x or TMN x active centers (x = 3 or 4). Six SACs are screened as promising NRR catalyst candidates with excellent activity and selectivity during NRR, and RuN 3 is identified as the optimal one with an overpotential of ≥0.10 V via the distal mechanism.
Methane is the major component in natural gas and flares wastefully at remote sites since the collection and use are not economical. The direct conversion of methane into liquid fuels such as methanol has been identified as a fruitful solution to this issue. Herein, density functional theory calculations and microkinetic studies were employed on 3d late-transition-metal atom (Fe, Co, Ni, Cu)-loaded graphyne as catalysts for methane-tomethanol conversion. Single metal atoms showed decent stability at pores of graphyne. The oxidant used for this work was abundant O 2 instead of high-cost H 2 O 2 or N 2 O. This systematic study revealed that both iron and cobalt single atoms dispersed at adjoining pores of graphyne are capable of forming catalytically active metal−oxygen (M−O) moieties upon dissociative adsorption of O 2 . Further, the Co−O moiety loaded on graphyne demonstrated reasonable catalytic activity for methane-to-methanol conversion with sufficient selectivity. Interestingly, dispersed single metal atoms on graphyne support were able to mimic the enzymatic formation of catalytically active M−O moieties. Moreover, it is further noticed that methane activation and methanol production kinetics are strongly correlated with the strength of the metal−oxygen bond.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.