High hydrogen selectivity and anti-carbon ability by cracking of RP-3 jet fuel over Pt/ZrO2-TiO2-Al2O3 catalyst modified by MxOy (MÂ =Â Ba, Sr and Ce) promoters

In order to improve the anti-carbon property and obtain higher H2 yields, the promoters (BaO, SrO and CeO2) were introduced into Pt/ZrO2-TiO2-Al2O3 catalyst. The activity of theses catalysts were investigated in the cracking reactions of RP-3 jet fuel under high temperature and high pressure conditions. The physicochemical characteristics of the catalysts were detected by Temperature programmed oxidation, Raman spectrum, N2 adsorption-desorption, Transmission electron microscope, NH3-temperature programmed desorption and NH3-infrared spectroscopy techniques. It was found that the addition of BaO, SrO and CeO2 promoted the well dispersion of Pt, stimulated the dehydrogenation reactions, and consequently higher hydrogen yields over modified catalysts were obtained. Moreover, the acid sites have been partially neutralized by these promoters, thus the total amount of acid sites as well as the Lewis acid sites decreased over the modified catalysts. The modified acidic properties inhibited the hydrogen transfer reactions and alkenes oligomerization reactions, resulting in the obvious decrease of carbon deposit. Therefore, the catalysts exhibited remarkable anti-carbon property after modifying by BaO, SrO and CeO2. The valuable information in this work may be helpful to develop highly efficient catalysts for the advanced aircrafts.