揭示Pd-Ag纳米颗粒尺寸对电催化甲醇氧化行为的影响

Exploring the relationship between the elemental distribution and electrochemical performance of nanoparticles, and revealing the involved mechanism is essential to the design of better electrocatalysts. Herein, high-temperature shock (HTS) is used to synthesize Pd-Ag nanoparticles with controllable sizes and mixing degree by applying different currents. Molecular dynamics is performed to simulate the structural evolution in the HTS process and establish the atomic model (PdxAg@Ag) for Pd-Ag nanoparticles, which is difficult to investigate with the conventional characterization methods. The Pd-Ag nanoparticles obtained under an applied current of 30 A exhibit the most outstanding specific activity for the methanol oxidation reaction (MOR) among all samples. By utilizing first-principles and random-walk simulation, the synergy between Pd and Ag is decoupled into the lower barrier of dehydrogenation and higher redox frequency of the Pd-Ag couple.