Mechanistic insights into methanol steam reforming on PdCu(111)and PtCu(111)bimetallic catalystsOA

Methanol steam reforming(MSR)stands as a pivotal process for efficient hydrogen production.In this study,density functional theory(DFT)calculations were employed to conduct a comparative analysis of the MSR reaction mechanism on PdCu(111)and PtCu(111)bimetallic surfaces.The investigation unveiled the underlying mechanism by which alloying modulates reaction pathways and overall catalytic performance.Notably,Cu sites were found to stabilize adsorption of OH and CH2O species,whereas Pd/Pt sites exhibited a preferential affinity for CO molecule.This spatial site separation facilitates progression along the formate pathway.PdCu(111)demonstrated superior overall catalytic performance compared to PtCu(111),with water dissociation identified as the rate-determining step(RDS),featuring an activation energy of only 0.74 eV.The bimetallic synergy breaks the inherent contradiction between the activity and selectivity of monometallic catalysts:Cu sites serve as a source of hydroxyl groups,while Pd/Pt sites enhance C–H bond cleavage efficiency,ultimately enabling high methanol conversion alongside low CO formation.From the perspectives of electronic structure and geometric configuration,this study establishes a theoretical framework to guide the rational design of high-performance bimetallic catalysts for MSR.