Synergy between single atom and nanoclusters promotes power and CO tolerant performance in PEMFCs

Pt-based catalysts are widely used in hydrogen oxidation reaction (HOR) for the anode of proton exchange membrane fuel cells (PEMFCs). However, high Pt loading and CO poisoning increase the overall cost and stringent requirements for fuel purity. Here, decreasing Pt usage while achieving high anode performance by anchoring Ni single atoms under or adjacent to Pt nanoclusters is studied. The electron interaction between oxophilic Ni single atoms and Pt nanoclusters is beneficial for optimizing the electrocatalytic HOR. The Pt-Ni SA /CNT-2.6 (CNT-carbon nanotube) catalyst with 2.6 wt% low Pt loading shows superior catalytic activity for the HOR, long-time stability, and good CO-tolerant performance in the liquid half-cell and fuel cell of membrane electrode assembly (MEA). Theoretical calculations reveal that the synergy between single atoms and nanoclusters optimizes the d band of Pt and decreases the activation barrier for HOR and CO stripping, thereby enhancing HOR activity and high CO tolerance in PEMFC anodes with a low Pt loading. This work provides a novel design of electron interactions between single atoms and Pt nanoclusters, showing a significant advantage in promoting low-Pt PEMFCs with high power and CO tolerance.