Oxidative dehydrogenation of ethylbenzene to styrene over zirconium vanadate catalyst prepared by solution combustion method

Abstract

A new type of mesoporous nanocrystalline vanadium incorporated zirconia material is synthesized by solution combustion method. The material is characterized by X-ray diffractometer (XRD), Brunanuer, Emmett and Teller (BET) surface area, Raman spectroscopy, and transmission electron microscopy (TEM) techniques. The XRD studies revealed the material to be a mixture of ZrO₂ and ZrV₂O₇. The effect of calcination temperature on the phase transformation of the materials has been investigated by XRD measurements. The material has been used as catalyst for oxidative dehydrogenation (ODH) of ethylbenzene (EB) using air as oxidant for the first time. A DFT modeling of the transition state of the reaction suggests the formation of a hydroxyl species over the catalyst surface which is believed to have been formed due to abstraction of a hydrogen atom from ethyl benzene. The presence of hydroxyl species on the catalyst surface has also been identified by FTIR record of the catalyst after treating it with ethyl benzene at 200 °C. A tentative mechanism for the reaction is proposed.