正己烷在ZnO／HZSM－5上的催化活性和脉冲反应动力学研究

用浸渍法制得系列ＺｎＯ／ＨＺＳＭ－５催化剂，ＸＲＤ结果表明，当ＺｎＯ含量低于５％时，ＺｎＯ以非晶相表面层形态存在于ＨＺＳＭ－５表面，含量超过１０％时，有ＺｎＯ晶相生成．用脉冲微反技术测定了正己烷在ＺｎＯ／ＨＺＳＭ－５上的催化活性，并且测得不同温度下正己烷在ＺｎＯ（１％）／ＨＺＳＭ－５上的表观速率常数，自表观活化能和色谱法测得的吸附热，求得表面反应活化能为１５０．７ｋＪ／ｍｏｌ．

STUDY ON CATALYTIC ACTIVITY AND PULSE REACTION KINETICS FOR N-HEXANE CONVERSION OVER ZnO/HZSM-5 CATALYSTS

A series of catalysts ZnO/HZSM-5 have been prepared by impregnation of HZSM-5 zeolite with zinc nitrate solutions, and studied by X-ray diffraction. It is shown that in the catalysts, as the ZnO content is less than 5 wt%,the ZnO appears on the surface of HZSM-5 zeolites as a non-crystalline layer,and as the ZnO content is more than 10 wt%, the crystalline ZnO appears. By the pulse microreaction technique, the catalytic activity of n-hexane over the catalysts has been determined,and the apparent rate constant of catan-hexane over ZnO(1% ) /HZSM-5 has been obtained at various temperatures. From the apparent activation energy and the adsorption heat obtained by chromatography, the activation energy of surface reaction has been calculated,the value is 150. 7 kJ/mol.