Ir-trimer anchored on the Co-supported Pd nanocrystals Opens the Ultra-efficient Channel on oxygen reduction reaction

Abstract

A novel type of Pt-free electrocatalysts composed of Co-supported Pd nanocrystals hierarchical structure with Ir-ensemble superficial doping, denoted as Co@Pd-Irn, is investigated using ab-initio method. The results elucidate the clinal distribution of the adsorption energy on the Co@Pd-Ir3 system predicts an Eads-oriented ultra-efficient loop from the Ir-trimer to its edge-area and the extended Pd atoms. Simulated kinetics verifies the abnormal ORR behavior with substantially reduced reaction barriers in the three key ORR subpaths, which wipes out the toughest barrier of the first “O2 dissociation”, outdistancing the benchmarking Pd and Pt. The scenarios of stress–strain distribution and physical charge relocation reveal the charge-regulating role of the superficially-doped Ir-trimer, which generates an unbalanced charge redistribution on the operated surface and the differentiated catalytic selectivity concerning the four crucial absorbates with different charge preference. A multi-level linkage of synergistic effect has been traced out that triggers a unique ORR mechanism of regional cooperative division, meanwhile manage to the cost control via dramatically slashing the expensive Pt up to the non-Pt level. Overall, our results provide novel insights into the design of commercial non-Pt metal nanocatalysts, offering a process window guidance with atomic-level accuracy on regulating the microstructure and composition of multi-metallic nanocatalysts.