SBA-15负载SnCl_(2)催化剂的制备及对环酮Baeyer-Villiger氧化反应的催化性能  

Preparation of SBA-15 supported SnCl_(2) catalysts and theircatalytic performances for Baeyer-Villiger oxidation of cycloketones

作　　者：魏玉丽 赵美玲 程建梅 WEI Yu-li;ZHAO Mei-ling;CHENG Jian-mei(College of Chemistry and Chemical Engineering,Lanzhou City University,Lanzhou 730070,Gansu,China)

机构地区：[1]兰州城市学院化学工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2023年第4期72-79,88,共9页Journal of Northwest Normal University(Natural Science)

基　　金：兰州城市学院博士科研基金资助项目(LZCU-BS2019-05)。

摘　　要：分别采用初湿浸渍法(IWI)和一锅法,制备了SBA-15和氨基功能化SBA-15负载锡Lewis酸中心的JZ-SnCl_(2)/SBA-15,SnCl_(2)/SBA-15及SnCl_(2)/NH 2-SBA-15系列催化剂.采用FT-IR,XRD,XPS,N_(2)吸附-脱附及TGA,SEM和TEM等手段对催化剂的结构和形貌进行了表征.结果表明,SnCl_(2)的引入并没有改变载体SBA-15的介孔结构,孔道通畅.其中用IWI法制备的JZ-SnCl_(2)/SBA-15中同时存在Sn(Ⅳ)和Sn(Ⅱ)两种Lewis酸中心,而用一锅法制备的SnCl_(2)/SBA-15中的Sn元素则主要以Sn(Ⅳ)形态存在.在一锅法制备的催化剂中,Sn元素在分子筛基质中分布均匀,Sn原子进入介孔孔壁形成了Sn-O-Si网络,提高了催化剂的热稳定性和化学稳定性.催化实验结果显示,JZ-SnCl_(2)/SBA-15和SnCl_(2)/SBA-15对以H_(2)O_(2)为氧化剂的金刚烷酮Baeyer-Villiger(B-V)氧化反应具有优异的催化活性.在二氯乙烷溶剂中,微波辐照5 min和8 min后,两种催化剂的催化活性分别为99%和92%,内酯产物的选择性均为100%,而且分别经6次和10次循环使用后,活性仍能保持68%和88%,而内酯选择性基本不降低.By using incipient wetness impregnation(IWI)method and one-pot method,SBA-15 and amino-functionalized SBA-15 supported SnCl_(2) catalysts JZ-SnCl_(2)/SBA-15,SnCl_(2)/SBA-15 and SnCl_(2)/NH 2-SBA-15 were synthesized.The textural analysis by FT-IR,XRD,XPS,N_(2) adsorption-desorption,TGA,SEM,and TEM showed that the prepared catalysts keep intrinsic mesoporous characterization of SBA-15 and the tunnels are unobstructed.JZ-SnCl_(2)/SBA-15 prepared by IWI method simultaneously possesses Sn(Ⅱ)and Sn(Ⅳ)Lewis acid sites,while the active sites of SnCl_(2)/SBA-15 obtained by one-pot method are mainly Sn(Ⅳ)species.At the same time,in the catalyst SnCl_(2)/SBA-15,Sn element is uniformly distributed in meso-sieve matrix and formed Sn-O-Si network,which can effectively improve thermal and chemical stability of the resulting catalyst.Two kinds of the prepared catalysts show excellent catalytic performance for Baeyer-Villiger(B-V)oxidation of adamantanone by H_(2)O_(2).After microwave irradiation in 1,2-dichloroethane for 5 and 8 min,conversion rates of the cycloketone on these two catalysts reach 99%and 92%,respectively,and lactone selectivity exceed 99%.Especially,they still possess excellent cyclic stability.After 6 catalysis cycles,JZ-SnCl_(2)/SBA-15 can maintain 68%of the initial activity without selectivity decrease while for SnCl_(2)/SBA-15 after 10 cycles 88%of the initial activity is kept without selectivity reduction.

关 键 词：SnCl_(2) Lewis酸催化剂 介孔氧化硅 Baeyer-Villiger氧化反应 环酮 

分 类 号：O624[理学—有机化学]