Pd／HM催化剂的制备及其表面酸性质

Ｐｄ／ＨＭ催化剂的制备及其表面酸性质徐忠民，苏运来，李全芝，胡家芬（复旦大学化学系，上海２００４３３）关键词钯／氢型丝光沸石，酸性质，氨－程序升温脱附，红外－程序升温脱附轻质烷烃的催化异构化是生产高辛烷值汽油的主要加工过程之一．自从Ｒａｂｏ等［１］发...

STUDIES OF PREPARATION AND SURFACE ACIDITY OF Pd/HM CATALYSTS

series of mordenites with different SiO2/Al2O3 ratios,different sodium ion exchange levels and different Pd contents were prepared. The effect of these factors on the number and strength of acid sites has been investigated by method of NH3-TPD and infrared spectrometer.The results show that the number and the strength of acid sites gradually decrease with increase of SiO2/Al2O3 ratios,and for the Bronsted and Lewis acid sites exists maximum when Al/u.c.=3.63.The IR results show that the distribution of surface acid sites of the mordenite is changed by supported Pd. The weak Bronsted acid sites and strong Lewis acid sites are increased;the strong Bronsted acid sites and weak Lewis acid sites are decreased. The effect of different exchange degrees of Na+ of Pd/HM on acidity indicates that the strong acid site will be exposed fully until the exchange degree reached to 99.9 %.