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研究了添加剂对用于选择性氧化正丁烷为顺丁烯二酸酐的VPO催化剂的结构和性能的影响 .催化剂采用共沉淀法制备 ,添加元素为Zr,Co ,Ce,Zn,Sn ,K ,Ba和Bi等 .催化剂性能测试在固定床微反应器内于常压下进行 .结果表明 ,添加剂对催化剂性能有很大的影响 .各种组分对正丁烷氧化的促活顺序为 :VPO Zr>VPO Co>VPO Zn >VPO Sn >VPO Bi>VPO Ce >VPO Ba >VPO K >VPO ,而对正丁烷氧化为顺丁烯的选择性促活顺序为 :VPO Zr>VPO Ce>VPO Zn >VPO Sn >VPO Co >VPO Bi>VPO >VPO Ba>VPO K .XRD ,FTIR和TGA/DTG测试结果表明 ,添加剂的加入并未使活化前后催化剂的本体结构发生明显改变 .所有VPO催化剂前体均主要含VOPO4·0 .5H2 O ,而活化后的催化剂主要含有 (VO) 2 P2 O7和少量α VOPO4.XPS测试证实催化剂表面有P ,V和O等元素富集的现象 ,而且表面氧物种数与催化剂活性直接相关
The effects of additives on the structure and properties of VPO catalysts for the selective oxidation of n-butane to maleic anhydride were studied.The catalysts were prepared by coprecipitation method with addition of Zr, Co, Ce, Zn, Sn, K, Ba and Bi etc. The catalyst performance test was carried out in a fixed bed microreactor at atmospheric pressure.The results showed that the additive had a great influence on the catalyst performance.The order of activation of n-butane oxidation for various components was VPO VPO> VPOb> VPOb> VPOb> VPOeC> VPOb> VPOk> VPO, whereas the selective activation order for the oxidation of n-butane to cis-butene is: VPOZr> VPOCe> VPO Zn> VPO Sn> VPO Co> VPO Bi> VPO> VPO Ba> VPO K. The results of XRD, FTIR and TGA / DTG tests showed that the addition of additives did not significantly change the bulk structure of the catalysts before and after activation. The bulk of the catalyst mainly contains VOPO4.0.5H2O, while the activated catalyst mainly contains (VO) 2 P2 O7 and a small amount of α VOPO4. The XPS test confirms the enrichment of P, V and O on the catalyst surface, and the surface oxygen The number of species is directly related to the activity of the catalyst