VO_x/SiO₂ Catalyst Prepared by Grafting VOCl₃ on Silica for Oxidative Dehydrogenation of Propane

Abstract

The VOx/SiO2 catalysts for oxidative dehydrogenation of propane were synthesized by a simple grafting method. The VOCl3 was first grafted at the surface of SiO2, which was dehydrated at different temperature (from 200 to 1000 °C). The formed grafted complexes were then calcined in air, leading to the formation of VOx/SiO2 catalysts. The synthesized catalysts were characterized by nitrogen adsorption, SEM, Raman spectroscopy, temperature‐programmed reduction, and extended X‐ray absorption fine structure analysis. The SiO2 pretreatment temperature has an evident effect on the loading and dispersion of VOx on SiO2, which finally affects their catalytic performance. High SiO2 treatment temperature is beneficial to dispersing the vanadium oxide species at the SiO2 surface. These materials are efficient catalysts for the catalytic oxidative dehydrogenation of propane to propylene. The best selectivity to propylene is achieved on the VOx/SiO2‐(1000) catalyst. The high selectivity and activity are well maintained for three days catalytic reaction.

Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

“…As a control, we immobilized W(C t Bu)(CH 2 t Bu) 3 ( A ) on nonporous silica SiO 2–700 particles (BET surface area = 183 m 2 g –1 ). 41 The resulting surface organometallic complex 0A displays a typical solid state 13 C CP MAS NMR spectrum of a monopodal single supported non- 13 C enriched tungsten [(SiO–)W(C t Bu)(CH 2 t Bu) 2 ]. 14 This spectrum was acquired without TEKPol solution impregnation and without DNP and it required a number of scans of 60 000 (Fig.…”

Morphology control of anatase TiO2 for well-defined surface chemistry

“…80 (b) VOCl 3 as a probe of hydroxyl reactivity. Vanadium oxychloride is a metal halide previously shown to exhibit a high reactivity towards the surface hydroxyls of metal oxides, 81 leading to the formation of surface vanadium species and hydrogen chloride through the following reaction:…”

Synthesis of V‐MCM‐41 Catalysts and Their Application in CO2‐Assisted Isobutane Dehydrogenation

“…To increase the catalytic performance, much research has been conducted to improve the dispersion of vanadium species . Among this research is the in situ synthesis of vanadium‐based mesoporous catalysts.…”