Tuning the base properties of Mg–Al hydrotalcite catalysts using their memory effect  

作　　者：Dahye Kwon Ji Yeon Kang Suna An Inchan Yang Ji Chul Jung 

机构地区：[1]Department of Chemical Engineering,Myongji University,Yongin 17058,Republic of Korea

出　　处：《Journal of Energy Chemistry》2020年第7期229-236,I0008,共9页能源化学（英文版）

基　　金：supported by C1 Gas Refinery Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(2015M3D3A1A01064908);supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2015R1D1A1A01059724)。

摘　　要：Herein,the relationship between the structure and base properties of Mg–Al hydrotalcite catalysts was comprehensively investigated in relation to heat treatment and rehydration processes,which are well known as memory effects of hydrotalcite.The structure of Mg–Al hydrotalcites changed from layered double hydroxide(LDH)to mixed metal oxide and subsequently to a spinel structure during heat treatment,and it was returned from mixed metal oxide to a LDH structure by rehydration.Based on various characterizations,we successfully proposed a detailed mechanism of memory effect.We also confirmed that the Mg–Al hydrotalcites had weak or strong base sites and that their base properties could be systematically tuned by heat treatment and rehydration.The prepared Mg–Al hydrotalcites were applied to a model reaction,isomerization of glucose to fructose,as base catalysts.Among the catalysts tested,the rehydrated Mg–Al hydrotalcite efficiently produced fructose due to its appropriate base and structure properties.We finally concluded that the base sites of Mg–Al hydrotalcites can be designed as desired by heat treatment and rehydration.Moreover,through systematic design of the base sites of Mg–Al hydrotalcites,these can be promising catalysts for various heterogeneous reactions over base catalysts,giving excellent catalytic performances.

关 键 词：Mg–Al hydrotalcite Structure Base properties Heat treatment REHYDRATION 

分 类 号：O643.36[理学—物理化学]