摘要
用固体离子交换法制备了V_2O_5/ZSM-5和V_2O_5/丝光沸石两类催化剂。通过XRD,LRS,XPS和Sg测定表征了V_2O_5在分子筛上的分散状态。用吡啶吸附红外光谱法和正丁胺非水溶液回滴法研究了催化剂的表面酸性。用ESR研究了甲苯在催化剂上的吸附。结果表明,催化剂的酸性不同,它们吸附甲苯的能力也不同,对甲苯气相选择氧化的活性和选择性也有较大的差异。同时,甲苯选择氧化成苯甲醛的能力还与V_2O_5在分子筛载体上的状态有关。
V2O5/ZSM-5 and V2O5/mordenite zeolite catalysts were prepared by solid-state ion exchange and their characteristics were studied by using XRD, LRS, XPS and surface area determination, their acid behavior was studied by using pyridine adsorption FT-IR and back titration with nonaqueous ?butylamine solution, and also the adsorption of toluene vapor on their surface was investigated by using ESR. The results suggest that their different capacities of toluene vapor adsorption are caused by their different acid behavior, and their activity and selectivity for toluene oxidation to benzaldehyde are different as well.
基金
国家自然科学基金
关键词
ZSM-5沸石
丝光沸石
五氧化二钒
ZSM-5 zeolite,mordenite,vanadium pentoxide,acidity,toluene oxidation,selectivity
