Multidentate-Phosphine Unlocks Active Ag Sites in Pt/PdAg14 Nanoclusters for Efficient Electrocatalytic Nitrate Reduction

Abstract

Catalysts with stable structures and exposed active sites are highly desirable for optimizing catalytic performance, yet their rational design remains a critical challenge in the field. Herein, we demonstrate that the diphosphine ligand 1,4bis(diphenylphosphino)butane (Dppb) can effectively trigger the exposure of active sites on the reported Pt/PdAg14(PR3)8(SR)6 nanoclusters, thereby inducing their structural transformation into Pt/PdAg14(Dppb)3(SR)6 nanoclusters.Benefiting from their unsaturated coordination environment and favorable electronic properties, the non-phosphinecoordinated Ag(SR)3 metal motifs serve as the dominant active centers for the electrocatalytic nitrate reduction reaction (NO3RR), which significantly facilitates the adsorption and activation of NO3 -. Notably, the core Pd and Pt atoms regulate the electronic configuration of the nanoclusters to promote the adsorption and activation of reaction intermediates, among which Pd doping exhibits superior modulation performance compared to Pt doping. This work not only clarifies the structureactivity relationship of ligand-engineered nanocatalysts but also highlights the synergistic strategy of ligand-regulated active site exposure and heteroatom doping as an effective approach for developing high-performance nanocatalysts toward sustainable environmental applications.2