Achieving complete electrooxidation of ethanol by single atomic Rh decoration of Pt nanocubes

The development of single site electrocatalysts such as single-atom catalyst (SAC) has demonstrated the advantages of high precious metal utilization and tunable metal-support interfacial properties. However, the fundamental understanding of unalloyed single metal atom decorated on a metallic substrate is still lacking. Herein, we report unalloyed single atomic, partially oxidized Rh on the Pt nanocube surface as the electrocatalyst to completely oxidize ethanol to CO₂at a record-low potential of 0.35 V. In situ X-ray absorption fine structure measurements and density functional theory calculations reveal that the single-atom Rh sites facilitate the C-C bond cleavage and the removal of the *CO intermediates. This work not only reveals the fundamental role of unalloyed, partially oxidized SAC in ethanol oxidation reaction but also offers a unique single-atom approach using low-coordination active sites on shape-controlled nanocatalysts to tune the activity and selectivity toward complicated catalytic reactions.