Understanding of Strain-Induced Electronic Structure Changes in Metal-Based Electrocatalysts: Using Pd@Pt Core-Shell Nanocrystals as an Ideal Platform

While metal-based electrocatalysts have garnered extensive attention owing to the large variety of enzyme-mimic properties, the search for such highly-efficient catalysts still relies on empirical explorations, owing to the lack of predictive indicators as well as the ambiguity of structure-activity relationships. Notably, surface electronic structures play a crucial role in metal-based catalysts yet remain unexplored in enzyme-mimics. Herein, the authors investigate the electronic structure as a possible indicator of electrocatalytic activities of H2O2 decomposition and glucose oxidation using Pd@Pt core-shell nanocrystals as a well-defined platform. The electron densities of the Pd@Pt are modulated with the correlation of strain through precise control of surface orientation and the number of atomic layers. The close relationships between the electrocatalytic activities and the surface charge accumulation are found, in which the increase of the electron accumulation can enhance both the enzyme-mimic activities. As a result, the Pd@Pt-3L icosahedra with compressive strain in Pt shells exhibit the highest electrocatalytic activities for H2O2 decomposition and glucose oxidation. Such systematic and comprehensive study provides the structure-activity relationships and paves a new way for the rational design of metal-based electrocatalysts. Especially, the charge accumulation degrees may serve as a general performance indicator for metal-based catalysts.

Automated summary

In this study, the authors investigated the impact of electronic structure on the electrocatalytic activities of H2O2 decomposition and glucose oxidation using Pd@Pt core-shell nanocrystals. They found close relationships between surface charge accumulation and catalytic activities, with an increase in electron accumulation enhancing enzyme-mimic activities. The study provides insights into structure-activity relationships and offers a new approach for the rational design of metal-based electrocatalysts, with charge accumulation degrees potentially serving as a general performance indicator for such catalysts.