用于丁烷选择氧化制顺酐的铈锆复合钒磷氧催化剂的研究

 在钒磷氧（VPO）催化剂中添加适量铈锆复合氧化物，得到了一\r\n种新型的铈锆复合钒磷氧催化剂．该催化剂对丁烷选择性氧化制顺酐反\r\n应的催化性能比纯VPO催化剂有了显著提高．在丁烷／空气共进料反应\r\n条件下，其顺酐收率比纯VPO催化剂提高了一倍；在无氧反应条件下，\r\n其可参与选择性氧化制顺酐的晶格氧量为纯VPO催化剂的2．2倍．BET比\r\n表面积测试、X射线衍射、钒平均价态测定和程序升温实验等表征结果\r\n表明，混合在催化剂活性相中的少量铈锆复合氧化物参与了VPO体系的\r\n氧化还原过程，并起到了以下两方面的作用：（1）促进了（VO）2P2O\r\n7相的形成，稳定了钒的平均价态，有利于最终形成晶相结构良好和反\r\n应性能稳定的VPO催化剂；（2）显著提高了VPO催化剂的氧化还原性能\r\n，大大增加了催化剂的可逆储氧量．

VPO Catalyst Doped with Ce-Zr Composite Oxide for n-Butane Selective Oxidation to Maleic Anhydride

A new VPO catalyst was prepared by doping with an appropriate amount of Ce Zr composite oxide. The doped catalyst possesses significantly improved catalytic performance compared with the pure VPO catalyst. In the n butane/air co feed reaction, the mole yield of maleic anhydride over the doped catalyst is doubled as compared with that over the pure VPO catalyst. In the absence of gas phase oxygen, the amount of lattice oxygen in the doped catalyst that is selective to maleic anhydride is 1 2 times higher than that in the pure VPO catalyst. The results of the BET surface area measurement, X ray diffraction, average vanadium valence measurement, and temperature programmed experiments show that a small quantity of Ce Zr composite oxide present in active phases of the catalyst takes part in the redox process of the VPO system. The addition of the Ce Zr composite oxide has two functions: (1) to promote the formation of (VO) 2P 2O 7 phase and maintain the average vanadium valence, which are in favor of obtaining the VPO catalyst with a good phase structure and stable catalytic performance; (2) to improve the redox property of the VPO catalyst remarkably and thereby increase the amount of reversible lattice oxygen stored in the catalyst dramatically.