Phosphotungstic acid immobilized on amino-functionalized TS-1 zeolite as a solid acid catalyst for the synthesis of tributyl citrate  

作　　者：Pei Li Bianfang Shi Junyao Shen Ran Cui Wenze Guo Ling Zhao Zhenhao Xi 

机构地区：[1]State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China [2]Key Laboratory of Smart Manufacturing in Energy Chemical Process,Ministry of Education,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第6期199-210,共12页中国化学工程学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(21978089);the Program of Shanghai Academic/Technology Research Leader(21XD1433000);Key Research and Development Program of Xinjiang Uygur Autonomous Region(2022B01032-1).

摘　　要：The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic bonding.The Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the modifications.The amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid sites.The tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid sites.An optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1%(mol)was achieved at 150℃for 6 h over the HPW immobilized on amino-functionalized TS-1.The catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

关 键 词：AMINO-FUNCTIONALIZATION Phosphotungstic acid TS-1 zeolite ESTERIFICATION Tributyl citrate 

分 类 号：TQ426[化学工程]