Optimized Adsorption of H and OH over Amorphous SrRuPtOH Nanobelts towards Efficient Alkaline Fuel Cell Catalysis.

PtRu-based catalysts toward hydrogen oxidation reaction (HOR) suffer from low efficiency, CO poisoning and over-oxidation at high potentials. In this work, an amorphization strategy is adopted for preparation of amorphous SrRuPtOH nanobelts (a-SrRuPtOH NBs). The a-SrRuPtOH NBs has optimized adsorption of intermediates (H and OH), increased number of active sites, highly weakened CO poisoning and enhanced anti-oxidation ability owing to the special amorphous structure. Consequently, a-SrRuPtOH NBs displays superior HOR performance with a mass activity of 7.5 A/mg, 25 and 5 times of that of SrRuPt(OH) NBs and commercial PtRu/C, respectively, and long-lasting stability. Besides, a peak power density of 750 mW/cm and a specific power of 14.8 W/mg have been achieved for a-SrRuPtOH NBs at a low loading of 0.05 mg/cm, surpassing many reported HOR catalysts. Mechanism investigation indicates that Pt and Ru are present in oxide/hydroxide forms and H in a-SrRuPtOH NBs participates in HOR. Ab initio molecular dynamics (AIMD) simulations and density functional theory (DFT) calculations show that there are three catalytic mechanisms participating in a-SrRuPtOH NBs, which all exhibit low catalytic barrier and highly improved HOR efficiency. This work provides a new strategy for designing high-performance catalysts towards fuel cells.