异丁烷选择氧化制甲基丙烯酸杂多化合物催化剂P1.33-dMo12VaCubSbcAsdK1.5Ox／SiC的研究

采用共沉淀法制备了一系列磷钼体系多组分催化剂P1.33-dMo12VaCubSbcAsdK1.5Ox／SiC（0.0≤a，b，c，d≤0.50）。利用XRD、FTIR、DSC、ESR等方法对催化剂的结构与性质进行了研究。XRD、FTIR的研究结果表明，合成的样品为具有Keggin杂多阴离子结构的磷钼杂多化合物。DSC，ESR测试结果表明催化剂具有较好的稳定性。同时考察了催化剂组分对异丁烷催化氧化性能的影响，结果表明，适量地引入V、As、Cu、Sb都能提高MAA（甲基丙烯酸）的选择性和MAA+MAL（甲基丙烯醛）的收率。催化剂P1.13Mo12V0.25Cu0.25Sb0.25As0.2K1.5Ox／SiC在360 ℃、常压、进料组成异丁烷：空气=1∶2（mol）、空速3 600 h－1条件下，异丁烷转化率10.7％，MAA+MAL的收率为6.8％。

STUDY ON HETEROPOLYCOMPOUND CATALYSTS FOR DIRECT OXIDATION OF ISOBUTANE TO METHACRYLIC ACID

In this parper, a series of P-Mo based multiple component catalysts, P1.33-dMo12VaCubSbcAsdK1.5Ox／SiC（0.0≤a，b，c，d≤0.50）, were prepared by co-precipitation method. The structure and properties of the catalysts were investigated by means of XRD，FTIR, DSC and ESR. The results of XRD and FTIR show that the catalyst is P-Mo heteropoly compound that possess Keggin heteropolyanion structure. The study of DSC and ESR indicate that the catalyst have good stability. The effect of content of catalyst on catalytic activity for isobutane oxidation was evaluated. It was found that the addition of V, Cu, Sb, As with appropriate amount can improve the selectivity of methacrylic acid and yield of MAA+MAL to some extent. For catalyst P1.13Mo12V0.25Cu0.25Sb0.25As0.2K1.5Ox／SiC, the conversion of isobutane is 10.7％, the yield of MAA+MAL is about 6.8％ under the reaction condition: 360 ℃, atmospheric pressure, feed composition: isobutane∶air=1∶2(mol), and GHSV=3 600 h－1.