Correlation between structure, acidity and activity of Mo-promoted Pt/ZrO2-TiO2-Al2O3 catalysts for n-decane catalytic cracking

Abstract

A series of Pt/MoO3/ZrO2-TiO2-Al2O3 composite oxides with various MoO3 contents were prepared by incipient wetness impregnation method, and coated on the inner wall of stainless-steel microchannels. Catalytic cracking of n-decane (as model molecule of hydrocarbon fuel) over such monolithic catalysts were investigated under high temperature and high pressure conditions. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS) and temperature programmed desorption of ammonia (NH3-TPD) techniques. The correlation between the catalytic performances of MoO3 modified catalysts and their structure as well as acidic property were observed. It was found that the conversion and heat sink of n-decane were obviously heightened compared with that obtained from thermal cracking. In particular, the catalyst which contains 7.0wt.% MoO3 exhibited the best catalytic cracking activity among the prepared catalysts, which is in well agreement with its highest amount of total acid sites and strong acid centers, along with the finely dispersed isolated and octahedral molybdenum species.