Morphological regulation of Pt/CeO₂ and its catalytic dehydrogenation of methylcyclohexane in fixed bed reactor

A series of Pt/CeO₂ compounds with hollow spheres (Pt/CeO₂–S), wires (Pt/CeO₂–W), and particle (Pt/CeO₂–P) morphologies were prepared and further used for catalytic liquid organic hydrogen carrier (LOHC) dehydrogenation. The exposure and distribution of different crystal faces affected the nucleation process of crystals and then formed different microscopic morphologies. Compared with Pt/CeO₂–W and Pt/CeO₂–P, Pt/CeO₂–S showed hollow spherical structures with significantly higher oxygen vacancy concentrations and specific surface areas. These structural differences not only affected platinum (Pt) dispersion, but also affected the activity and stability of the catalyst, thus promoting methylcyclohexane (MCH) conversion. The fixed bed reaction showed that Pt/CeO₂–S had excellent catalytic activity, with the MCH conversion rate at 97.7 % and hydrogen release rate of 350.50 mmol/g_(Pt)/min, and it still maintained stable activity after 72 h. Under the same conditions, the MCH conversion rates for Pt/CeO₂–W and Pt/CeO₂–P were only 77.23 % and 32.02 %, respectively. Therefore, through the growth pattern and morphology controls of catalyst supports, this was an effective means for improving the dehydrogenation performance of LOHC.