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用浸渍法制备了负载型复合杂多酸催化剂H4SiW12 O40 -La2 O3/γ -Al2 O3,用于甲醇脱水制备二甲醚 .用N2 吸附、吡啶吸附红外光谱、NH3-TPD、XRD光谱等手段对催化剂进行了表征 .考察了杂多酸负载量、浸渍时间、反应温度、质量空速等因素对催化活性的影响 .实验结果表明 :催化剂中H4SiW12 O40 负载量为 1 0 %～ 1 6%时催化剂的活性最好 ;在常压下反应温度为 3 0 0℃ ,质量空速为 1 0h- 1时 ,甲醇转化率达 85% ,二甲醚的选择性为 99 9% ;加压可提高催化剂的活性 .
The supported composite heteropolyacid catalyst H4SiW12 O40 -La2 O3 / γ -Al2 O3 was prepared by impregnation method, which was used for the dehydration of methanol to prepare dimethyl ether. The effects of N2 adsorption, pyridine adsorption infrared spectroscopy, NH3-TPD and XRD spectra The effect of heteropoly acid loading, impregnation time, reaction temperature, mass space velocity and other factors on the catalytic activity was investigated.The experimental results show that when the catalyst loading of H4SiW12 O40 is 10% ~ 16% The reaction temperature is 3000 ℃ and the mass space velocity is 10h-1, the conversion of methanol is 85% and the selectivity of dimethyl ether is 99.9%. The pressure can increase the catalyst Activity.