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

Abstract

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 to-wards 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.