{"title":"水对活性MgAl水滑石活性和稳定性的影响","authors":"Yuanzhou Xi, Robert J. Davis","doi":"10.1016/j.jcat.2007.12.008","DOIUrl":null,"url":null,"abstract":"<div><p><span><span>Magnesium–aluminum hydrotalcite with a Mg/Al molar ratio of 4 was synthesized by a coprecipitation method. Thermally-decomposed and rehydrated Mg–Al hydrotalcites were used to catalyze the </span>transesterification of tributyrin, a model triglyceride, with methanol (tributyrin:methanol molar ratio 1:30) at 333 K to produce methyl butyrate, monobutyrin, dibutyrin, and glycerol. The pseudo first order rate constants of a three step reaction sequence for tributyrin transesterification were determined by fitting a kinetic model to the experimental data. Although decomposed and rehydrated Mg–Al hydrotalcite was one order of magnitude more active than decomposed Mg–Al hydrotalcite based on surface area measured by N</span><sub>2</sub> adsorption, the activity correlated well to the CO<sub>2</sub><span> adsorption capacity. The most active rehydrated samples also deactivated faster, presumably because butyric acid produced by hydrolysis of ester with adsorbed water reacted with the base sites. The areal rate and CO</span><sub>2</sub> adsorption capacity of decomposed-rehydrated Mg–Al hydrotalcite decreased as the interlayer water was removed by heating.</p></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"254 2","pages":"Pages 190-197"},"PeriodicalIF":6.5000,"publicationDate":"2008-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jcat.2007.12.008","citationCount":"96","resultStr":"{\"title\":\"Influence of water on the activity and stability of activated MgAl hydrotalcites for the transesterification of tributyrin with methanol\",\"authors\":\"Yuanzhou Xi, Robert J. Davis\",\"doi\":\"10.1016/j.jcat.2007.12.008\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span><span>Magnesium–aluminum hydrotalcite with a Mg/Al molar ratio of 4 was synthesized by a coprecipitation method. Thermally-decomposed and rehydrated Mg–Al hydrotalcites were used to catalyze the </span>transesterification of tributyrin, a model triglyceride, with methanol (tributyrin:methanol molar ratio 1:30) at 333 K to produce methyl butyrate, monobutyrin, dibutyrin, and glycerol. The pseudo first order rate constants of a three step reaction sequence for tributyrin transesterification were determined by fitting a kinetic model to the experimental data. Although decomposed and rehydrated Mg–Al hydrotalcite was one order of magnitude more active than decomposed Mg–Al hydrotalcite based on surface area measured by N</span><sub>2</sub> adsorption, the activity correlated well to the CO<sub>2</sub><span> adsorption capacity. The most active rehydrated samples also deactivated faster, presumably because butyric acid produced by hydrolysis of ester with adsorbed water reacted with the base sites. The areal rate and CO</span><sub>2</sub> adsorption capacity of decomposed-rehydrated Mg–Al hydrotalcite decreased as the interlayer water was removed by heating.</p></div>\",\"PeriodicalId\":346,\"journal\":{\"name\":\"Journal of Catalysis\",\"volume\":\"254 2\",\"pages\":\"Pages 190-197\"},\"PeriodicalIF\":6.5000,\"publicationDate\":\"2008-03-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.jcat.2007.12.008\",\"citationCount\":\"96\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Catalysis\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0021951707004630\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Catalysis","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021951707004630","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Influence of water on the activity and stability of activated MgAl hydrotalcites for the transesterification of tributyrin with methanol
Magnesium–aluminum hydrotalcite with a Mg/Al molar ratio of 4 was synthesized by a coprecipitation method. Thermally-decomposed and rehydrated Mg–Al hydrotalcites were used to catalyze the transesterification of tributyrin, a model triglyceride, with methanol (tributyrin:methanol molar ratio 1:30) at 333 K to produce methyl butyrate, monobutyrin, dibutyrin, and glycerol. The pseudo first order rate constants of a three step reaction sequence for tributyrin transesterification were determined by fitting a kinetic model to the experimental data. Although decomposed and rehydrated Mg–Al hydrotalcite was one order of magnitude more active than decomposed Mg–Al hydrotalcite based on surface area measured by N2 adsorption, the activity correlated well to the CO2 adsorption capacity. The most active rehydrated samples also deactivated faster, presumably because butyric acid produced by hydrolysis of ester with adsorbed water reacted with the base sites. The areal rate and CO2 adsorption capacity of decomposed-rehydrated Mg–Al hydrotalcite decreased as the interlayer water was removed by heating.
期刊介绍:
The Journal of Catalysis publishes scholarly articles on both heterogeneous and homogeneous catalysis, covering a wide range of chemical transformations. These include various types of catalysis, such as those mediated by photons, plasmons, and electrons. The focus of the studies is to understand the relationship between catalytic function and the underlying chemical properties of surfaces and metal complexes.
The articles in the journal offer innovative concepts and explore the synthesis and kinetics of inorganic solids and homogeneous complexes. Furthermore, they discuss spectroscopic techniques for characterizing catalysts, investigate the interaction of probes and reacting species with catalysts, and employ theoretical methods.
The research presented in the journal should have direct relevance to the field of catalytic processes, addressing either fundamental aspects or applications of catalysis.