Confined environment of RhCu catalyst to regulate the reaction performance for synthesis gas conversion to CHx
The selectivity of syngas-to-C2 oxygenates still faces a big challenge.Using density functional theory calculation methods,this study explores the influence of the confined environment of Rh active sites on the reaction performance of syngas conversion to CHx over four types of RhCu confined catalysts,which further reveals the essential reasons of the confinement effect to regulate the catalytic performance.The results showed that the confined environment of Rh active sites in the RhCu confined catalysts can regulate the activity and selectivity of syngas conversion to generate CHx.The screened RhGCN5.5 catalyst could perform the highest catalytic activity toward syngas conversion to generate CHx(x=1-3)monomer.The moderate confinement effect of RhGCN5.5 catalyst made the d-band center of surface atoms far away from the Fermi level,leading to an appropriate electron gain and loss between the transition state of CH2OH dissociation and RhCu surface,which was conducive to the dissociation of CH2OH into CH2 and thus exhibited excellent CHx formation activity.This study provides theoretical basis for improving the catalytic performance of syngas conversion to C2 oxygenates by adjusting the confined environment of active site and provides the structural clues for the design of the confined metal single-atom catalysts.
confined catalystconfined environmentsyngasCHxdensity functional theory