Mo/HZSM-5丙烷芳构化催化性能及其吸附量热的研究

采用等量浸渍法制得一系列不同担载量的Ｍｏ／ＨＺＳＭ－５催化剂，运用ＸＲＤ和ＦＴＩＲ方法考察了Ｍｏ物种在催化剂表面的分散状态，首次采用微分吸一热技术对Ｍｏ／ＨｚＳＭ－５催化剂的表面酸性进行表征。同时研究了催化剂对丙烷芳构化的反应活性。结果表明：对于担载Ｍｏ的ＨＺＳＭ－５分子筛催化剂，Ｍｏ物种在ＨＺＳＭ－５分子筛表面上顺序为ＨＺＳＭ－５〉１％Ｍｏ／ＨＺＳＭ－５〉２％Ｍｏ／ＨＺＳＭ－５分子筛本身表面的酸

CATALYSIS PROPERTY OF PROPANE AROMATIZATION OVER Mo/HZSM-5 CATALYSTS AND MICROCALORIMETRY ADSORPTION STUDY

A series of Mo/HZSM-5 catalysts were prepared by incipient wetness impregnation method with various of Mo loadings The dispersion of Mo species on catalysts surface was investigated by XRD and FTIR The surface acidity property of Mo/HZSM-5 catalysts was characterized by microcalorimetry adsorption technique first time, and the activity of propane aromatization reaction over those catalysts was also studied It was found that when the HZSM-5 catalysts modified by Mo was used, Mo species dispersed on the HZSM-5 surface covered the stronger acid sites of HZSM-5 zeolite surface to decrease the surface acidity The order of acid strength decrease is HZSM-5>1%Mo/HZSM-5>2%Mo/HZSM-5>5%Mo/HZSM-5 It is favorable to the formation of propane aromatization product that Mo species disperse highly on the HZSM-5 surface in HZSM-5 aperture structure with the appropriate strength acid sites The activity order of catalysts is 2%Mo/HZSM-5>1%Mo/HZSM-5>5%Mo/HZSM-5 It is found that only when both of the acidity and the Mo loading of catalysts are appropriate, the catalytic activity of the Mo/HZSN-5 catalysts can be optimum