Methanol Oxidaiton over the Nanoscale Supported Tungsten Oxide Catalysts
Nanoscale supported tungsten oxide catalysts were synthesized by hydrothermal method using γ-Al2O3, Nb2O5, TiO2, ZrO2 and CeO2 as supports with a loading of 5~20% WO3 on each supports, respectively. The physical properties and structural information were characterized by BET, XRD, ICP-AES and in situ Raman spectroscopy. Raman results confirm that the desired molecular arrangements of the active surface WOx species have been achieved without the presence of the crystalline WO3 phase. The reactivity/selectivity of the supported WOx catalysts are chemically probed with steady-state methanol oxidation reaction. The catalytic results of methanol oxidation reaction have revealed that the acid sites are present on the surface of WOx/Al2O3, WOx/Nb2O5, WOx/TiO2 and WOx/ZrO2 catalysts for the mainly production of dimethylether (DME), and redox sites have only present on the surface of the WOx/CeO2 catalysts for the oxidation production of formaldehyde (HCHO). In addition, the WOx/CeO2 catalysts possesses the high redox reactivity and the WOx/Al2O3 catalyst possesses the highest acid reactivity.
Zhong Cao, Lixian Sun, Xueqiang Cao, Yinghe He
Y. M. Dai et al., "Methanol Oxidaiton over the Nanoscale Supported Tungsten Oxide Catalysts", Advanced Materials Research, Vols. 233-235, pp. 1460-1463, 2011