Alumina-supported highly dispersed platinum–copper nanocatalyst with good dehydrogenation performance for perhydromonobenzyltoluene as a hydrogen carrier

Abstract

Precious metal catalysts are widely used in the field of heterogeneous catalysis in general and, in particular, for the dehydrogenation process of liquid organic hydrogen carriers (LOHCs). However, improving their catalytic activity and selectivity simultaneously is challenging owing to the characteristics of transition metals. Herein, a catalyst, namely, Pt_2.5Cu_0.1/Al₂O₃-H₂, was developed that could break the negative correlation between catalytic activity and selectivity, improving the overall dehydrogenation performance and reducing costs. This method achieved highly dispersed nanoparticles (NPs) and co-localization to form a unique PtCu_x alloy with reduced Pt electron density by anchoring low loadings of Cu-doped Pt on an alumina support. It also suppressed strong metal support interactions (SMSIs), as confirmed by characterization results such as XPS and HRTEM, resulting in excellent bimetallic synergistic catalytic dehydrogenation activity and selectivity in perhydromonobenzyltoluene (12H-MBT), compared with Pt_2.6/Al₂O₃-H₂. The reaction energy barrier for the dehydrogenation of 12H-MBT was relatively low (∼94 kJ mol⁻¹), and the rate-determining step of the whole catalytic dehydrogenation was identified to be 4H-MBT → 0H-MBT.