在十二钨磷酸上甲醇转化为甲醚的研究

Studies on the conversion of methanol into dimethyl ether on H3PW12O40

采用真空原位透射红外、常压色谱-TPD、高真空质谱-TPD、活性测试等方法研究了甲醇在十二钨磷酸上的吸附和反应。结果表明,甲醇在十二钨磷酸(H_3PW_(12)O_(40))上存在着两种处于平衡的吸附态,对应于分子态的脱附和解离态的脱附,脱附峰温分别为120℃和370℃,分子态的脱附活化能Ed=33.7kJ/mol。提出了甲醇在H_3PW_(12)O_(40)上催化制甲醚的可能机理。活性实验得到了甲醇分别在H_3PW_(12)O_(40)和活性炭担载的H_3PW_(12)O_(40)上催化成甲醚的产率随温度和空时变化的曲线,初步探讨了工业生产甲醚的可行性。

The conversion of methanol into dimethyl ether (DME) on H_3PW_(12)O_(40) has been studied by in situ transmission FT-IR, gas chromatography ( GC ) -temperature programmed desorption ( TPD ) , high vacuum mass spectrometry ( MS )-TPD and in a continuous flow-system for measuring catalytic activity. The results have shown that there are two adsorbed states of methanol existing on H_3PW_(12)O_(40), which correspond to the molecular state and dissociated state and desorb at 120℃ and 370℃ respectivly. The Ed of molecular state is found to be 33.7 kJ/mol and reaction mechanism for formation of DME has been suggested. The catalytic activities of methanol to DME on H_3PW_(12)O_(40) and H_3PW_(12)O_(40)/C have been measured and the feasibility of industry production of DME has also been discussed.