Carbon-Encapsulated Single-Atom Platinum Nickel Alloy for Efficient and Durable Alkaline Hydrogen Oxidation Through Enhanced Charge Polarization

Developing efficient and stable non-noble metal electrocatalysts for fuel cells is pivotal yet challenging. Herein, a dual-modulation strategy by integrating a single-atom alloy (SAA) core with carbon encapsulation to fabricate an advanced NiPtSA@NC catalyst is proposed, which exhibits an impressive specific activity of 82.0 mu A cm-2 and superior stability for alkaline hydrogen oxidation reaction (HOR). Experimental and theoretical investigations unveil that the superior HOR performance is due to the enhanced water adsorption and optimized hydrogen binding energy over the dual-modulated Ni active centers with a moderately downshifted d-band center, which stems from the charge polarization triggered by the introduced Pt atoms, creating an electron-rich local environment for Pt atoms while electron-depletion for Ni atoms, as well as inducing electrons transfer from the metallic core to the carbon shell. This study provides an effective dual modulation strategy to construct robust non-noble metal electrocatalysts for HOR, guiding the catalyst design of other related catalytic reactions. This work presents a novel dual modulation strategy involving single-atom alloy and carbon encapsulation for alkaline HOR. The resulting NiPtSA@NC catalyst exhibits impressive specific activity and superior stability for alkaline HOR through enhanced charge polarization. image