考察了分子筛的类型、硅铝比及Cu和Pd改性对分子筛催化剂上二甲醚低温水解活性的影响. 结果表明,酸性的MCM-22和HZSM-5分子筛催化剂具有较高的二甲醚水解活性,且其活性随着分子筛硅铝比的增加而降低. 这表明分子筛的类型及酸性对催化剂性能有重要影响,具有超笼结构的MCM-22分子筛上B酸中心的良好可接近性,使得该分子筛催化剂的水解活性较相同硅铝比的HZSM-5分子筛高. 与改性前相比, Cu和Pd改性后的MCM-22催化剂显示出更高的二甲醚水解活性.
The catalytic performance of various zeolite catalysts for dimethyl ether (DME) hydrolysis was investigated. The aim is to obtain a highly active catalyst for hydrolysis of DME at low temperature, which can be coupled with the Cu-Pd/AC catalyst to construct a bifunctional catalyst for coupling the DME hydrolysis with methanol carbonylation. The results showed that the acidic zeolite catalysts HZSM-5 and MCM-22 exhibited DME hydrolysis activity at relatively low temperatures. Compared with HZSM-5, the good accessibility of the strong Brnsted acid sites located in MCM-22 super cages was responsible for higher conversion of DME. Further improvement in the catalytic activity was found on the MCM-22 catalyst modified by transition metals Pd and Cu.
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