Single-Crystalline Mesoporous Alloy Family with Large Tunable Mesopores for High-Efficient Peroxide-like Enzyme Catalysis

Single-crystalline mesoporous alloys (SMAs) have attracted great research attention for applications in catalysis, energy storage, and nanomedicine, owing to their abundant mesopores, long-range coherent crystalline framework, and multimetallic synergistic effect. However, the control of SMAs with large mesopores, high-energy surfaces, and tunable compositions is still a great challenge. Herein, a family of cubic single-crystalline mesoporous alloys (CSMAs) including bimetallic PtPd, trimetallic PtPdRh, PtPdFe, PtPdNi, tetrametallic PtPdNiIr, PtPdRhHf, PtPdRhIr, PtPdRhFe, and pentametallic PtPdRhFeHf CSMAs is prepared for the first time. These CSMAs are synthesized via a triblock copolymer micelle-guided cogrowth approach, where ethanedioic acid (EA) is introduced to help the formation of high-energy surfaces. The mesoporous diameters of the CSMAs are systematically adjusted from 6.3 nm to as high as 18.4 nm by expanding the micelle volumes at different temperatures. The CSMAs with spherical mesopores, strip mesopores, and raspberry-like structures are further prepared by modulating the hydrophobic/hydrophilic ratios of triblock copolymers. As a proof of concept, the prepared PtPdRhFe CSMAs exhibit excellent specific activity and significantly enhanced peroxidase (POD)-like activity compared to previously reported Pt-based multimetal materials.