摘要
采用等pH值沉淀及共沉淀法制得助剂Al(OH)_3胶、Al(OH)_3-Mg(OH)_2胶、Al(OH)_3-Zn(OH)_2胶及活性组分,按一定重量比湿法混合均匀,经煅烧活化后制得含不同助剂的挤条催化剂.用全玻璃外循环无梯度反应器、XRD 和加速老化等技术对这些催化剂进行考察.结果表明,助剂的引入使催化剂的挤条机械强度得到改善,比表面在不同程度上增大;铝胶助剂易与活性组份中的二价元素生成铝酸盐,阻碍了铁酸盐尖晶石的生成,但助剂中有Mg(OH)_2或Zn(OH)_2存在时阻碍作用大大减小;XRD 可检测到催化剂主要由铁酸盐尖晶石相和α-Fe_2O_3相组成;含助剂的催化剂抗老化性明显优于不含助剂的样品及工业催化剂.
The additives and main components of catalysts were prepared by precipitationor coprecipitation from nitrate with ammonia water at constant pH values respectively,fol-lowed by filtering,washing.Then the obtained matters were completely mixed in desiredratio,dried,decomposed at 300℃ for 6h,calcined at 650℃ for 16h.Several techniques in-cluding external recycle reactor,XRD and accelerated aging were used to characterize thesecatalysts.The results show that surface area increases and mechanic strength improves withthe additives put in.Al(OH)_3(gel)has the preference for solid reaction with ZnO leading tothe formation of spinel phase ZnAl_2 O_4 and prohibits the formation of spinel phase ferrite;Al(OH)_3-Mg(OH)_2(gel)and Al(OH)_3-Zn(OH)_2(gel)retard this solid reaction.XRDspectra show the catalysts promoted by additive consist of the main phase ferrite spinel andminor phase α-Fe_2 O_3. The promoted catalysts,aged under the same condition,possesshigher relative activities than the unpromoted and commercial catalysts.
出处
《北京服装学院学报（自然科学版）》
CAS
北大核心
1992年第2期8-13,共6页
Journal of Beijing Institute of Fashion Technology：Natural Science Edition
关键词
丁烯氧化脱氢
铁酸盐催化剂
助剂
oxidative dehydrogenation of butene
ferrite catalyst
spinel
additives
