CO spillover on ultrathin bimetallic Rh/Rh-M nanosheets

Rh has been regarded as a promising catalyst for ethanol-oxidation reaction (EOR). Nevertheless, Rh is vulnerable to CO poisoning. In this work, we demonstrate a facile strategy for constructing a unique class of ultrathin Rh/Rh-M nanosheets, on which CO can diffuse from the Rh site to the M site. Detailed experiments, characterizations, and theoretical simulations have been conducted to validate the CO spillover effects on Rh/Rh-M nanosheets (NSs). Moreover, the significance of the CO spillover effect has been demonstrated by catalyzing the EOR, where Rh/Rh-M NSs with CO spillover display much higher activity, higher CO 2 selectivity, and stronger resistance to CO poisoning compared with pure Rh NSs. Consequently, the Faraday efficiencies (FEs) of CO 2 of the optimal catalyst (e.g., Rh 79 Co 21 NSs) are 70.3% and 75.5% at 0.7 and 0.8 V RHE , respectively, and these are much higher than those of Rh NSs (62.0% and 64.3% at 0.7 and 0.8 V RHE , respectively). • A versatile strategy for the fabrication of Rh/Rh-M nanosheets • CO can spill from Rh-site to M-site Rh/Rh-M nanosheets • CO spillover effect enhances the stability of Rh to CO poisoning • Rh-Co nanosheets display promising performance for ethanol oxidation Noble metals generally suffer from deactivation due to their strong adsorption abilities to some poisoning intermediates, such as CO. Despite great efforts that have been devoted to the modification of noble-metal catalysts to regulate their surface properties to prevent them from being poisoned, it is challenging to balance the activity, selectivity, and stability of noble-metal catalysts. In this work, we have successfully fabricated a unique class of ultrathin Rh/Rh-M (M = Co, Mn, Fe, and Ni) nanosheets with a strong CO spillover effect for enhanced catalysis. Benefitting from the specific structures of Rh/Rh-M nanosheets (NSs), CO can spill from Rh sites of ultrathin Rh nanosheets to M sites of RhM nanoparticles, which leads to the weakened CO adsorption on Rh sites and strengthened CO adsorption on M sites. This work provides a facile strategy for strengthening the resistance to CO poisoning through the CO spillover effects, which may attract great interests of researchers in diverse fields. A facile strategy for fabricating the ultrathin Rh/Rh-M (M = Co, Mn, Fe, and Ni) nanosheets were proposed. Owing to the unique structures, CO can spillover from the Rh site to the M site on ultrathin Rh/Rh-M nanosheets, leading to significantly strengthened resistance to CO poisoning and enhanced ethanol-oxidation reaction performance.