Ni/HZSM-5的结构及催化木糖醇水相加氢合成液体烷烃的性能研究  

Ni/HZSM-5 Bi-functional Catalysts:Structure and Performance of Aqueous-Phase Reforming of Xylitol for Liquid Alkane

作　　者：江婷[1,2] 章青[1] 王铁军[1] 张兴华[1,2] 张琦[1] 马隆龙[1] 

机构地区：[1]中国科学院可再生能源与天然气水合物重点实验室,中国科学院广州能源研究所,广州510640 [2]中国科学院研究生院,北京100049

出　　处：《无机化学学报》2012年第5期971-978,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家973计划课题(No.2012CB215304);国际科技合作专项(No.S2012ZR0159);国家自然科学基金(No.51076157)资助项目

摘　　要：采用浸渍法制备了Ni/HZSM-5双功能催化剂,采用BET、XRD、NH3-TPD、H2-TPR、FTIR和TG等方法表征了催化剂比表面、孔结构、酸性、还原能力及骨架结构等信息,研究了其催化木糖醇水相加氢合成液体烷烃的性能及催化剂失活的原因。结果表明,在优化的金属中心/酸中心的协同作用下,木糖醇可通过水相加氢高选择性地合成C5-C6烷烃;过高的金属中心或酸中心均会导致C-C键断裂形成轻质烷烃,以2%Ni/HZSM-5催化剂上木糖醇水相加氢活性最高,木糖醇C转化率为94%液体烷烃总收率可达90%,这与其具有较大的比表面积、合适的孔径分布、较多的金属活性中心、适中的酸量和强酸量有关。催化剂6次重复使用后活性明显降低,其骨架部分脱铝和表面积碳是其失活的主要原因。Bi-functional Ni/HZSM-5 with different Ni loadings were prepared and characterized by BET, XRD, NH3-TPD, H2-TPR, FTIR and TG techniques. Effects of metal and acid active sites on the catalyst structure and catalytic performance of aqueous phase reforming of xylitol for liquid alkanes production were studied. The results showed that C5-C6 alkanes could be effectively obtained by dehydration and successive hydrogenation of xylitol on the optimized coupling of the metal and acid sites. 2% Ni/HZSM-5 catalyst exhibited the maximal xylitol conversion of 94% and liquid alkanes yield of 90%. Moreover, the surface area and pore volume of thus catalyst were found to be in favor for the reaction. Appropriate amount of metal active sites and acid were also observed in the 2% Ni/HZSM-5 catalyst, which could promote the dehydrogenation and successive hydrogenation of xylitol into alkanes. In addition, the catalyst deactivated heavily after six recycle runs, which might be attributed to the partial dealumination of zeolite framework and coke formation on the surface of the catalyst.

关 键 词：Ni/HZSM-5 木糖醇 水相加氢 液体烷烃 

分 类 号：O643.3[理学—物理化学] O614.813[理学—化学]