有序介孔碳载金属催化剂用于择形催化  

Ordered Mesoporous Carbon Supported Metal Nano Catalysts for Shape-Selective Catalysis

作　　者：朱小娟[1] 孙雅飞 王丽丽[1] 吴萌萌 万颖[1] ZHU Xiaojuan;SUN Yafei;WANG Lili;WU Mengmeng;WAN Ying(Shanghai Frontiers Science Center of Biomimetic Catalysis,Shanghai Key Laboratory of Rare Earth Functional Materials,Key Laboratory of Resource Chemistry of Ministry of Education,Shanghai Non-Carbon Energy Conversion and Utilization Institute,Shanghai Normal University,Shanghai 200234,China)

机构地区：[1]上海师范大学,上海非碳基能源转换与利用研究院,资源化学教育部重点实验室,上海市稀土功能材料重点实验室,上海市仿生催化前沿科学研究基地,上海200234

出　　处：《化学反应工程与工艺》2022年第5期420-430,共11页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(22025204,92034301);上海市教育委员会科研创新计划资助(2021-01-07-00-02-E00119)。

摘　　要：择形催化在精细化学合成等领域发挥着重要作用。有序介孔材料具有相对大的孔径以及规整的孔道结构,探究其在有机合成中择形催化性能具有重要意义。本研究考察了有序介孔碳载AuPd合金催化剂的孔径对苄醇选择氧化和喹啉选择加氢反应中分子尺寸选择催化性能的影响。结果表明:有序介孔碳催化剂介孔孔径与反应物分子尺寸之间存在明显的正依存关系。苯甲醇和喹啉等尺寸较小的底物分子可扩散进入3.5 nm的介孔孔道,在合金表面反应;而尺寸较大的分子如2-甲基苄醇和3,5-二叔丁基苄醇,内扩散受到限制,几乎不能发生转化。当孔径扩大至5.0 nm时,2-甲基苄醇可扩散进入孔道,催化氧化的转化频率(TOF_(Pd))可达307 h^(-1);进一步扩大孔径至6.0 nm,尺寸更大的分子如3,5-二叔丁基苄醇也能被氧化,TOF_(Pd)达到140 h^(-1)。Shape-selective catalysis plays an important role in fine chemical synthesis and other fields.Ordered mesoporous materials have relatively large pore diameters and regular pore structures,and it is of great significance to explore their shape-selectivity.Here,the effect of the pore size of the ordered mesoporous carbon confined AuPd alloy catalyst on the selective oxidation of benzyl alcohol compounds and the selective hydrogenation of quinoline compounds was studied.The results clearly showed the relationship between molecular size of substrate and mesopore size of catalyst.Small-sized substrate molecules such as benzyl alcohol and quinoline could diffuse into the mesoporous pores of 3.5 nm and oxidation/reduction on the surface of the alloy;while the inner diffusion of larger molecules such as 2-methylbenzyl alcohol,and 3,5-di-tert-butylbenzyl alcohol were seriously inhibited resulting in undetectable conversion.When the pore size increases,larger molecules could diffuse into mesopores and accessible to the metal sites.The turn-over frequency(TOF_(Pd))of 2-methylbenzyl alcohol oxidation could reach 307 h^(-1) in the catalyst with 5.0 nm-pores and TOF_(Pd) for the oxidation of 3,5-di-tert-butylbenzyl alcohol is 140 h^(-1) in a 6.0 nm-pore mesoporous catalyst.

关 键 词：择形催化 分子尺寸 有序介孔碳 金属催化剂 

分 类 号：O643.322[理学—物理化学]