Ligand-controlled exposure of active sites on the Pd1Ag14 nanocluster surface to boost electrocatalytic CO2 reduction

Advancing catalyst design requires meticulous control of nanocatalyst selectivity at the atomic level. Here, we synthesized two Pd₁Ag₁₄ nanoclusters: Pd₁Ag₁₄(PPh₃)₈(SPh(CF₃)₂)₆ and Pd₁Ag₁₄(P(Ph-p-OMe)₃)₇(SPh)₆, each with well-defined structures. Notably, in Pd₁Ag₁₄(P(Ph-p-OMe)₃)₇(SPh)₆, the detachment of a phosphine ligand from the top silver atom facilitates the exposure of singular active sites. This exposure significantly enhances its selectivity for the electrocatalytic reduction of CO₂ to CO, achieving a Faraday efficiency of 83.3% at -1.3 V, markedly surpassing the 28.1% performance at -1.2 V of Pd₁Ag₁₄(PPh₃)₈(SPh(CF₃)₂)₆. This work underscores the impact of atomic-level structural manipulation on enhancing nanocatalyst performance.