Mesoporous multimetallic nanospheres with exposed highly entropic alloy sites

Multimetallic alloys (MMAs) with various compositions enrich the materials library with increasing diversity and have received much attention in catalysis applications. However, precisely shaping MMAs in mesoporous nanostructures and mapping the distributions of multiple elements remain big challenge due to the different reduction kinetics of various metal precursors and the complexity of crystal growth. Here we design a one-pot wet-chemical reduction approach to synthesize core-shell motif PtPdRhRuCu mesoporous nanospheres (PtPdRhRuCu MMNs) using a diblock copolymer as the soft template. The PtPdRhRuCu MMNs feature adjustable compositions and exposed porous structures rich in highly entropic alloy sites. The formation processes of the mesoporous structures and the reduction and growth kinetics of different metal precursors of PtPdRhRuCu MMNs are revealed. The PtPdRhRuCu MMNs exhibit robust electrocatalytic hydrogen evolution reaction (HER) activities and low overpotentials of 10, 13, and 28mV at a current density of 10mAcm(-2) in alkaline (1.0M KOH), acidic (0.5M H2SO4), and neutral (1.0M phosphate buffer solution (PBS)) electrolytes, respectively. The accelerated kinetics of the HER in PtPdRhRuCu MMNs are derived from multiple compositions with synergistic interactions among various metal sites and mesoporous structures with excellent mass/electron transportation characteristics. Nanostructured materials made from multimetal alloys are attractive for catalytic applications. Here, the authors propose a soft-templating approach to prepare mesoporous PtPdRhRuCu nanospheres that feature exposed porous structures rich in highly entropic alloy sites.

Automated summary

In this study, core-shell PtPdRhRuCu mesoporous nanospheres (PtPdRhRuCu MMNs) were synthesized using a one-pot wet-chemical reduction approach with a diblock copolymer as the soft template. The PtPdRhRuCu MMNs showed adjustable compositions and exposed porous structures rich in highly entropic alloy sites. Electrochemical characterization revealed robust electrocatalytic hydrogen evolution reaction (HER) activities of the PtPdRhRuCu MMNs in alkaline, acidic, and neutral electrolytes.