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本文目的在于研究稀土铈对钼酸铋的丙烯选择氧化影响.不同比例的催化剂呈现了比较复杂的动力学行为.随着催化剂组成变化,氧反应级数可由零级经过0.5级直至无一定反应级数,对丙烯的反应级数也随组成改变有很大变化.为解释这一现象,本文提出了统一反应机理,即随着催化剂组成变化,催化剂表面活性中心由晶格氧经历吸附原子态氧至吸附分子态氧变化.通过X光、红外及其它实验结果表明,预期这样的活性中心变化是由于铈的存在形成了钼酸铈晶相,破坏了钼酸铋晶体形成而促使钼酸铋更加分散缘故.
The purpose of this paper is to investigate the effect of rare earth cerium on propylene selective oxidation of bismuth molybdate.The catalysts with different proportions exhibit more complex kinetic behavior.With the change of catalyst composition, the oxygen reaction order can be from zero to 0.5 without any reaction Number, the reaction order of propylene also changes greatly with the composition change.In order to explain this phenomenon, this paper presents a unified reaction mechanism, that is, as the composition of the catalyst changes, the catalyst surface active center by the lattice oxygen undergoes the adsorption of atomic oxygen To X-ray, infrared and other experimental results show that such activity center is expected to change is due to the presence of cerium cerium molybdate phase, the destruction of bismuth molybdate crystal formation and to promote more bismuth molybdate Scattered sake.