Selective ring opening of decalin with Pt–Ir on Zr modified MCM-41

Abstract

Selective ring opening of decalin over the catalysts comprising of Ir in combination with Pt supported on mesoporous material, Zr–MCM-41 was studied in a trickle bed reactor. The Zr substituted MCM-41 (Si/Zr = 5) support was synthesized by hydrothermal method and characterized by BET surface area measurement, XRD, FTIR, TPD of ammonia. XRD showed hexagonal nature of MCM-41. TPD of ammonia and DRIFTS of ammonia adsorption spectra, respectively, showed moderate acidity and presence of Lewis and Brønsted acid sites. Zr–MCM-41 catalysts loaded with Ir and Pt in the range of 0–1.5 wt.% were prepared and characterized by DRIFT spectroscopy of CO adsorption, DRIFT of NH3 and TEM. The activity and selectivity of Ir/Pt-loaded Zr–MCM-41 were investigated in the ring opening of decalin in the temperature range of 300–400 °C at 5 MPa in the presence of hydrogen. Increase in Ir loading significantly increased the ring opening products yield and selectivity. Maximum conversion of 55 wt.% obtained at 400 °C. In the range of operating conditions studied, the optimum loading for better ring opening yield of 15 wt.% was 1.5 wt.% Ir and 0.75 wt.% Pt.