A series of Al2O3@SBA-15 composites with different alumina loadings have been prepared using a solid-state grinding method. Various techniques, such as X-ray diffraction, N2 sorption, FT-IR spectroscopy, and NMR spectroscopy, are used to characterize their structures and acidity. The Al2O3@SBA-15 composites retain the mesostructure of the SBA-15 host and the alumina is highly dispersed and uniformly coated inside the mesopores. The Al2O3@SBA-15 composites serve as remarkable supports for Pt nanoparticles, which can be used as catalysts in the enantioselective hydrogenation of ethyl pyruvate. Both the Brønsted acid sites that originate from the interface of Al2O3 and SBA-15 in the Al2O3@SBA-15 composites and the appropriate interaction of Pt nanoparticles with alumina coated inside the mesopores of SBA-15 can improve the catalytic behavior of Pt/Al2O3@SBA-15 catalysts.