Naphtha catalytic cracking to olefins over zirconia–titania catalyst

A zirconia–titania-based catalyst was synthesized by a co-participation method to study the catalytic cracking of heavy naphtha (dodecane) into high value-added olefins. The nanocrystal-sized catalysts were characterized and the cluster consisted of tetragonal ZrO2 incorporated into anatase TiO2. The catalyst was stable from hydrogen reduction while the surface acidity was increased as more ZrO2 was incorporated into the TiO2 framework. The catalytic cracking of naphtha was increased as the moderate catalytic acidity strength increased and the 50% Zr–Ti oxide catalyst delivered higher conversion between 85–95% with olefin yield around 55–60%. The surface acidity of the Zr–Ti catalyst promoted more cyclization reactions to produce benzene, toluene, and xylene (BTX). The study investigated steam catalytic cracking, which was slightly improved using a lower acidic Zr–Ti catalyst, while the propylene/ethylene ratio was unchanged. The time-on-stream study highlighted the stability of the catalyst with ZrO2 incorporated into the TiO2 framework, to promote olefin yield from naphtha catalytic cracking.