“One stone three birds” of a synergetic effect between Pt single atoms and clusters makes an ideal anode catalyst for fuel cells

Abstract

An inexpensive and highly efficient anode electrocatalyst for the hydrogen oxidation reaction (HOR) with high tolerance toward O₂ and CO is highly desirable for the commercialization of H₂/O₂ proton-exchange membrane fuel cells (PEMFCs). In this study, we report an atomically dispersed Pt catalyst (Pt–C–AA, with Pt 1.70 wt%) containing both Pt single atoms and tiny Pt₄ clusters. It was found to be highly active (1148 mW cm⁻²) for the HOR in a PEMFC, and also presented remarkable durability and tolerance to both O₂ and CO during the HOR process under the working conditions. Further analysis along with DFT calculations revealed that such a high performance could be attributed to a new “one stone three birds” mechanism of a synergetic effect between Pt single atoms and the neighboring Pt₄ clusters: one “win–win” mode for HOR and two “lose–lose” modes for the poisoning from both CO and O₂. Such a unique synergetic effect hugely and selectively enhanced the HOR activities and anti-CO/O₂ abilities, suggesting Pt–C–AA is one of the most promising or ideal anode catalysts for the HOR in PEMFCs. It is also the first pure Pt-based anode electrocatalyst that can satisfy all three requirements for its practical application in fuel cells. The work here reveals a new mechanism of a novel synergetic effect and a new strategy for the design of highly efficient functional materials.