V5+物种对钒磷氧化物催化性能的影响

采用有机相法制备钒磷氧化物催化剂，通过空气或氧气气氛中不同时间的原位预处理以系统调变样品中V⁵⁺物种的含量及其状态，并考察对催化正丁烷选择氧化制马来酐的反应性能的影响。理化表征手段的结果表明，空气或氧气预处理改变了V物种的价态及V⁵⁺/V⁴⁺的相对含量，但对催化剂的比表面积和表面P/V比没有显著影响。表面V⁵⁺/V⁴⁺的合适比例及相应的结构状态可能在V⁵⁺-V⁴⁺物种之间产生较好的协同作用，从而获得较为理想的催化反应性能。

Influence of the V5+ Species on the Catalytic Performance of the Vanadium Phosphorous Oxide Catalysts

The VPO catalysts synthesized in the organic medium were carefully in situ treated in air and oxygen atmosphere in order to systematically adjust the content and structural features of the V5 species existing in the catalyst and to study their influence on the reaction performance for the partial oxidation of n butane to maleic anhydride. The characterization and evaluation results indicated that controllable treating the catalysts in air or oxygen changed the oxidation state of the vanadium species and the ratio of the V5 /V4 , but less affected the particle size and the surface P/V ratio of the catalysts. Appropriate amount of V5 to V4 species in the sample and the suitable dispersed state/structural feature of the V5 species could lead to an optimized synergistic interaction between V4 and V5 species, which is the key factor accounting for the notably improved catalytic performance.