Titania-Supported Vanadium Oxide Synthesis by Atomic Layer Deposition and Its Application for Low-Temperature Oxidative Dehydrogenation of Propane

Abstract

Vanadium oxide supported on TiO2(P25) catalysts were synthesized via atomic layer deposition (ALD) of vanadyl acetylacetonate (VO(acac)2). Comprehensive investigations were performed to evaluate the ALD temperature window and the saturation deposition period of VO(acac)2, which were found to be 140–210 °C and 120 min, respectively. The synthesized catalysts were compared to their corresponding impregnation ones for the oxidative dehydrogenation of propane reaction (ODH-P). The ODH-P results indicated the superior performance of the ALD catalysts for the low temperature ODH-P (< 350 °C) given its better dispersion of vanadium oxide(vanadia) in the ALD catalysts. Several characterization techniques including HR-TEM, FE-SEM, XRD, BET, XPS, O2-chemisorption, ICP-OES, and H2-TPR were utilized to evaluate the influence of the ALD and impregnation methods of synthesis on different features of the catalysts. It was observed that the ALD method could offer far better dispersion of the active phase on the support of the catalyst, which is beneficial for the catalytic performance. Variations of Hacac, acetone, and CO2 FTIR absorbance peaks’ areas versus the support temperature