A series of Al2O3 supported and Pt-based metal catalysts were prepared using an equal volume saturation co-impregnation method, applied for the dehydrogenation of 12H-benzyltoluene (12H-MBT)liquid Organic Hydrogen Carrier(LOHC). In order to reduce the surface acidity of as-prepared catalysts, low-acidity hydroxyapatite support, addition of a second metal active components, and high temperature calcination Al2O3 supports were applied for the design and preparation of catalysts. The physical and chemical properties of the catalyst were characterized using NH3-TPD, XRD, BET, and HRTEM, the characterization results indicate that the acidity of as-prepared catalysts modified by the above three methods is lower than that of the 0.5Pt/Al2O3-500-8 catalyst which has no modification, and the higher the calcination temperature of Al2O3 support, the lower the acidity of as-prepared catalysts.The optimized 0.5%Pt-0.2%Sn/Al2O3-700-8 catalyst shows high catalytic activity and selectivity for the 12H-monobenzyltoluene dehydrogenation. At the reaction temperature of 320°C, the 12H-monobenzyltoluene dehydrogenation rate exceeds 85% and the selectivity of the completely dehydrogenated product 0H-monobenzyltoluene is more than 94%. The light component by-product content in the dehydrogenation product is less than 0.24%, and the heavy component by-product content is less than 0.54%.