超细Fe-V-O催化剂上甲苯液相氧化制苯甲醛

分别采用共沉淀法,凝胶自燃烧法和水热法制备了Fe-V-O复合氧化物催化剂用于催化过氧化氢液相氧化甲苯制苯甲醛反应中,并采用N2等温吸附-脱附法,粉末X射线衍射,红外光谱,扫描电子显微镜,能量弥散X射线光谱和H2程序升温还原等方法对催化剂性质进行了表征.结果表明,制备方法显著影响催化剂的结构,比表面积,形貌,表面元素组成和还原性.Fe-V-O催化剂颗粒的超细化调变了其比表面积和还原性,从而改善了催化剂上甲苯液相氧化制苯甲醛反应性能.其中水热法制备的超细Fe-V-O催化剂具有最高的苯甲醛收率和较好的重复使用性能.这主要归因于该催化剂颗粒尺寸小,比表面积大,以及表面较多的活性钒氧物种和适宜的还原性.

Superfine Fe-V-O Catalyst for Liquid-Phase Oxidation of Toluene to Benzaldehyde

Iron-vanadium oxide catalyst(Fe-V-O) samples were prepared by co-precipitation,gel combustion,and hydrothermal method,respectively.The catalytic activity of the as-prepared catalyst in the liquid-phase oxidation of toluene by hydrogen peroxide was tested.In addition,the physicochemical properties of these samples were characterized by N2 adsorption-desorption,powder X-ray diffraction,Fourier transform infrared spectroscopy,scanning electron microscopy,energy dispersive X-ray spectroscopy,and H2 temperature-programmed reduction.The preparation method significantly affected the structure,specific surface area,morphology,surface V/Fe ratio and reducibility of the as-prepared catalyst samples.Fe-V-O sample prepared by hydrothermal method exhibited the highest benzaldehyde yield and better reusability compared with other investigated samples,due to its smaller particle size,larger specific surface area,higher V/Fe surface ratio and the moderate reducibility.