论文部分内容阅读
采用固体离子交换法制备了Cu(Ⅰ ) /沸石双功能羰基化催化剂 ,以CO ,吡啶和NH3 为探针分子 ,用原位FT IR和TPD方法研究了活性中心的性质和作用机理 .结果表明 ,在Cu(Ⅰ ) /Hβ沸石双功能催化剂中存在固体酸和金属羰基两类活性中心 ,其中B酸中心的数量可以用Cu+ 交换来进行调变和控制 ,而金属羰基活性中心则分布在两类不同的位置上 ,分别构成Cu+ 与Cu+ (CO)以及Cu+ (CO)与Cu+ (CO) 2 两个可逆的动态平衡 ,平衡移动时伴随着CO的吸收和释放 .本文的研究结果支持两类活性中心协同催化的机理 ,即固体酸中心使醇质子化形成正碳离子后 ,金属羰基活性中心协同催化 ,最终形成羧酸或羧酸酯
The Cu (Ⅰ) / zeolite bifunctional carbonylation catalyst was prepared by solid ion exchange. The CO and pyridine and NH3 were used as probe molecules to study the nature and mechanism of the active site by in situ FT-IR and TPD methods. , There are two kinds of active centers of Cu (Ⅰ) / Hβ zeolite bimetallic catalyst, including solid acid and metal carbonyl. The number of B acid centers can be modulated and controlled by Cu + exchange, while the metal carbonyl active centers are distributed in two (CO) and Cu + (CO) 2 and Cu + (CO) 2 respectively at different positions of the same species, which are accompanied by the absorption and release of CO during the equilibrium movement.The results of this paper support two types of The active center synergistic catalysis mechanism, namely the solid acid center makes the alcohol protonated to form the positive carbon ion, the metal carbonyl active center cooperates catalysis, finally forms the carboxylic acid or the carboxylate