摘要
用IR、TPD、TEM图片研究了H4SiW12O40-Ti(SO4)2-La2O3-HZSM-5的酸性质和表面性质,并与催化甲醇成二甲醚的活性和选择性进行了关联。结果表明,H4SiW12O40-Ti(SO4)2-La2O3-HZSM-5存在着B酸位与L酸位。催化剂的总酸度与甲醇转化率和二甲醚产率有关。反应温度180℃时有最佳的酸催化能力。Keqqin结构的[SiW12O40]4-不能渗入HZSM-5分子筛的孔径,而是完全沉积在HZSM-5分子筛的表面。
The surfacial acidic properties of H4SiW12O40-Ti(SO4)2-La2O3-HZS-M-5 have been studied by means of IR,TPD and TEM,and referred to the activity and selectivity of the catalyst for methanol to dimethylether. The result shows that there are Bronsted and Lewis acid sites in H4SiW12O40-Ti(SO4)2-La2O3-HZSM-5,and that the total acidity of the catalyst has much to do with the conversion of methanol and the yield of dimethlether. 180℃ is the best suitable temperature. Keggin unit [SiW12O40]4-cannot penetrate the HZSM-5 pore system but merely becomes deposited on the external HZSM-5 surface.
基金
国家自然科学基金
吉林省科委资助项目
