Effect of CeO2 redox properties on the catalytic activity of Pt-CeOx over irreducible SiO2 support for methylcyclohexane (MCH) dehydrogenation

A highly reducible CeO2 surface was prepared on a SiO2 support to investigate the effect of redox properties of CeO2 on the catalytic activity of Pt/CeO2-SiO2 for MCH dehydrogenation. Characterization of the Pt/CeO2-SiO2 catalyst revealed a significantly higher Pt dispersion than Pt/micro-sized CeO2 and Pt/SiO2. The well-dispersed Pt particles averaging 1.1 nm in size (Pt/CeO2-SiO2) were primarily attributed to the high surface concentration of oxygen vacancies, which provided abundant defect sites that stabilized the Pt particles from sintering. Hydrogen released from MCH dehydrogenation was approximately 5–6 times greater with high selectivity towards toluene products for Pt/CeO2-SiO2 compared to its counterparts. The excellent catalytic activity of Pt/CeO2-SiO2 was attributed to the presence of rich oxygen vacancies on the CeO2 surface, which was significantly reduced under MCH dehydrogenation conditions, resulting in faster toluene desorption.