高比表面介孔MoVTeNbO催化剂的制备及其催化性能

采用水热法添加模板剂十六烷基三甲基溴化铵(CTAB)和配合剂柠檬酸(CA)制备了Mo VTe Nb O系列催化剂,并将其应用于丙烯一步氧化制备丙烯酸的反应.结果表明,CA的添加量对催化剂的形貌、孔结构、比表面积及催化性能具有明显的影响.当n(CA)/n(Mo)=0.36时,Mo VTe Nb O催化剂为介孔纳米催化剂,其平均孔径为4.9 nm,具有较高的比表面积(37.8 m2/g)和较小的催化剂晶粒(粒径范围为10~16 nm),与常规水热法制备的催化剂相比,Mo VTe Nb O介孔纳米催化剂的晶粒变小、催化性能得到了显著提高,丙烯一步氧化制丙烯酸的转化率可由53.9%提高至71.2%,丙烯酸收率可提高到45.8%.

Preparation of High Specific Surface Mesoporous MoVTeNbO Catalyst and Its Catalytic Properties

MoVTeNbO catalysts were prepared by hydrothermal method with template agent cetyl trimethyl ammonium bromide (CTAB) and complexing agent citric acid (CA). The prepared catalysts were then applied to one step oxidation of propylene to acrylic acid. The results showed that the morphology, pore structure, specific surface area and catalytic performance of the catalysts were significantly affected by the amount of CA. The mesoporous and nano MoVTeNbO catalyst with average pore size of 4.9 nm, larger specific surface area of 37.8 m2/g and smaller catalyst grain size of 10-16 nm was obtained at n(CA)/n(Mo) of 0.36. Compared with conventional catalysts prepared by hydrothermal method, the catalytic performance of the mesoporous and nano MoVTeNbO catalyst was superior. When it was used for one step oxidation of propylene, the propylene conversion could be increased from 53.9% to 71.2%, and the yield of acrylic acid could be increased to 45.8%.