A bimetallic strategy to modulate electronic metal support interaction in Co₃O₄(111)-based catalysts: the case of...

The electronic metal support interaction (EMSI) plays a decisive role in determining the activity, selectivity, and stability of noble metal catalysts supported on reducible oxides. While EMSI can enhance catalytic performance, excessively strong charge transfer at the metal/oxide interface often leads to oxidation and disintegration of metal nanoparticles, particularly in systems such as Rh/Co₃O₄(111). In this work, we explore how bimetallic Rh-Pt interactions modulate and counteract EMSI at the Rh/Co₃O₄(111) interface. Two types of core-shell Rh-Pt nanoparticles with precisely controlled compositions and architectures were prepared on well-ordered Co₃O₄(111) thin films on an Ir(100) substrate and investigated using synchrotron radiation photoelectron spectroscopy. We found that incorporating Pt, either as the core in Pt@Rh or as the shell in Rh@Pt nanoparticles, significantly attenuates charge transfer, thereby stabilizing Rh in its metallic state and suppressing disintegration of the core@shell nanoparticles. This stabilization is attributed to strong Rh-Pt interaction and the ability of the two metals to form stoichiometric binary phases. These findings demonstrate that bimetallic interactions offer an effective strategy to tune EMSI, providing a fundamental basis for the design of electronically balanced and thermally stable catalysts supported on reducible oxides.