氧化钨歧化催化剂中活性物种的价态研究及高活性催化剂的制备

项目名称： 氧化钨歧化催化剂中活性物种的价态研究及高活性催化剂的制备

项目编号： No.21306227

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 化学工业

项目作者： 姜伟丽

作者单位： 中国石油大学（北京）

项目金额： 25万元

中文摘要： 丙烯短缺状况的加剧致使歧化制丙烯技术受到广泛的关注。多相氧化钨歧化催化剂由于具有价格低廉、稳定性高等优势倍受青睐，但其活性偏低，且反应中活性物种的价态仍不明确，不仅影响到对反应机理的推测，也影响了催化剂制备和反应条件的选择。本项目拟从可控还原价态研究与低价氧化钨催化剂制备两方面对活性物种的价态及制备条件进行研究。首先采用H2-TPR与XPS相结合的方式对WO3/SiO2催化剂进行可控还原及活性研究，探索氧化钨的价态与还原条件以及催化活性的关系。其次采用还原W(VI)的方法制备纳米低价氧化钨，以介孔硅分子筛为载体制备高分散度的负载型和掺杂型低价钨催化剂；分析不同氧化钨的价态、制备方法（负载型和掺杂型）及金属助剂改性对催化剂活性的影响。最终探明催化剂中活性物种的价态，揭示活性物种的产生及作用机理；并提出制备高活性氧化钨催化剂的适宜方法，为低能耗的丙烯生产技术提供实验依据。

中文关键词： 氧化钨；歧化；丙烯；多相催化剂；价态

英文摘要： The olefin metathesis technique, which offers a method to produce propylene, has been more widely researched in recent years as the aggravation of propylene shortage. Among the stable heterogeneous metathesis catalysts, WO3-based catalyst becomes the most competitive one because of its lower price, higher stability and so on, but with lower activity. A key problem to this catalyst that the valence of the active species is not definite not only affects the deduction on mechanism, but also affects the selection for catalyst preparation conditions. Herein, we plan to pre-reduce WO3/SiO2 controlly together with preparing tungsten oxide catalyst with lower valence to study the valence of active species and the preparation conditions. Firstly, H2-TPR and XPS techniques are to be used to build the relationship between tungsten valence and reduction conditions, and further that between tungsten valence and catalysis activity in the pre-reduction of WO3/SiO2. On the other hand, stable slight-reduced tungsten oxide nanoparticles are going to be prepared by reducing W(VI) precursor. Meso-porous silicon will be synthesized as support to prepare supporting type and doping type catalysts with low-valence tungsten oxide and high dispersity. Furthermore, the influence of different tungsten valence, preparation methods (supporti

英文关键词： tungsten oxide；metathesis；propylene；heterogeneous catalyst；valence