Cu/MoO_3-TiO_2/SiO_2上光催化CO_2和C_3H_8合成异丁烯醛的研究

Photocatalysis Reaction for Synthesizing Methacrolein from Propane and CO_2 over Cu/MoO_3-TiO_2/SiO_2 Catalyst

采用表面改性法和等体积浸渍法制备了金属修饰的负载型复合半导体材料Cu/MoO3-TiO2/S iO2,用X射线衍射、比表面积测定、红外光谱、拉曼光谱和紫外-可见漫反射等技术对固体材料的结构、吸光性能和化学吸附性能进行了表征,研究了该材料对CO2和丙烷合成异丁烯醛的光促表面催化规律.结果表明,半导体活性组分MoO3和TiO2在所制备的催化剂Cu/MoO3-TiO2/S iO2表面形成化学键,并存在多种活性吸附位;金属Cu的修饰拓展了固体材料对光源的响应范围,提高了反应体系的吸光能力;固体材料对CO2和丙烷的有效吸附使其在较低温度下就能促进异丁烯醛的紫外光化学合成,反应选择性达到85%左右.根据实验结果对光促CO2和丙烷表面催化合成异丁烯醛的机理进行了讨论.

Solid material of metal-decorated coupled semiconductors Cu/MoO3-TiO2/SiO2, prepared by the chemical modification method and the isovolumetrie impregnation method, was introduced into photo-promoted surface reaction （PPSR） process to synthesize methaerolein from propane and carbon dioxide. BET, XRD, TEM, IR, Raman and UV-Vis DRS experiments were used to characterize the surface structure, photon absorbing and ehemisorbing ability of the material. It was shown that the semiconductors TiO2 and V205, dispersed well on the surface of the catalyst Cu/MoO3-TiO2/SiO2, can be coupled each other by the chemical bonds and form manifold active ehemisorbed sites. The decoration of metal Cu is helpful to expend the light-responding scope of the material, which can also improve the photo absorbing ability of the whole reaction. The active chemisorbing of CO2 and propane on the catalyst greatly promotes the photochemical synthesis of methaerolein and the selectivity of methaerolein can reach 85%, even at the lower temperature. On the basis of the experiments, the mechanism of photo-promoted surface reaction for synthesizing methaerolein from C3H8 and CO2 on Cu/MoO3-TiO2/SiO2 was discussed.