Synthesis of M/Ti-MCM-41 Photocatalyst and Study on Its Performance of Hydrogen Production

摘要

Highly crystalline and mesoporous titanium-incorporated Ti-MCM-41 zeolite was prepared using hexadecylpyridinium bromide (CPBr) as structure-directing agents and tetrabutyl orthotitanate (TBOT) as the source of the heteroelements. A series of transition metal (V, Cr, Mn, Fe, Co, Ni, Cu, Zn) oxide loaded on Ti-MCM-41 (M/Ti-MCM-41) catalysts were synthesized by impregnation method. Some physicochemical techniques, such as N2 physisorption, X-ray diffraction (XRD), diffuse reflectance UV-vis spectra (DR. UV-vis), laser Raman spectra, and X-ray fluorescence analysis (XRF), were used to characterize these binary transition metals modified M/Ti-MCM-41 photocatalysts. The M/Ti-MCM-41 photocatalysts, except V/Ti-MCM-41, showed higher hydrogen production activities than pure Ti-MCM-41 in the ethanol-water system under the irradiation of 300 W high-pressure mercury lamp, especially, the yield of hydrogen of Co/Ti-MCM-41 (62.02 μmol H_2/h) was at least 4 times higher than that of Ti-MCM-41 (15.43 μmol H_2/h). However, only the Cr/Ti-MCM-41 photocatalyst exhibited a detectable activity under visible light. This work demonstrated how photodecomposition of H_2O was affected by loading of transition metal oxides onto the mesoporous Ti-MCM-41.