【摘要】 用原位红外技术、等温吸附、程序升温脱附、X射线光电子能谱研究了HZSM-5和磷改性的ZSM-5分子筛的酸性质和表面性质,并与催化乙醇制乙醚的活性和选择性进行了关联。结果表明,样品的总酸度与乙醚产率和乙醇转化率有关。磷的掺入使酸度增加,酸强度降低,有利于乙醚产率的提高和抑制副产物乙烯及积炭的生成。更多还原

【Abstract】 In situ infrared spectroscopy, adsorption isotherms, temperature programmed desorption and X-ray photoelectron spectroscopy have been used to investigate the acidic and surface properties of HZSM-5 and phosphorus-modified ZSM-5 zeolites. The catalytic conversion of ethanol to diethyl ether over above-mentioned zeolites has been studied by continuous flow technique and chromatography. It is found that both Bronsted and Lewis acid centers of ZSM-5 type zeolites have a bearing on the conversion of ethanol to diethyl ether. The yield of diethyl ether and the optimum reaction temperature depend on the total acidity and acid strength of samples respectively. The change in selectivity has been tentatively assigned to slight modification of channel size and to change in acid strength due to phosphorus compound bonding to the zeolite framework. The catalytic activity measurement shows that the addition of phosphorus to ZSM-5 zeolite prevents coke deposit.更多还原