高活性固体碱Na2O/Al2O3-MgO的合成与表征
Synthesis and Characterization of Solid Base Catalyst Na2O/Al2O3-MgO with High Activity
作者单位E-mail
刘守庆 西南林业大学理学院, 昆明 650224  
李雪梅 西南林业大学理学院, 昆明 650224  
和献武 西南林业大学理学院, 昆明 650224  
刘祥义 西南林业大学理学院, 昆明 650224 13577068220@126.com 
郑志锋 西南林业大学材料工程学院, 昆明 650224 zhengzhifeng666@163.com 
摘要: 过量NaOH易引起铝离子流失,造成以Al2O3-MgO为载体的催化剂性能不稳定,为此以NH3为沉淀剂制备了Mg-Al共沉淀物,进而通过Na2CO3浸渍、老化、焙烧处置,制备了Na2O/Al2O3-MgO催化剂,借助XRD、SEM、SEM-EDS、TG-DSC、N2吸附-脱附等手段对其结构及形貌进行表征,以蒜头果油甲酯化率对其活性进行评价,结果表明:采用共沉淀-浸渍的处理方法可以获得类水滑石片层结构的催化剂前驱体,该前驱体主要分解温度在200~500 ℃之间,经高温煅烧处理后所得催化剂中有Na-Al及Na-Mg-Al氧化物形成。制备高活性Na2O/Al2O3-MgO催化剂的条件为:镁铝离子比nMg/nAl=3:1~1:3、老化时间12 h、焙烧温度550 ℃、焙烧时间5 h。以nMg/nAl=1:1时制备的催化剂进行验证实验发现,所得催化剂比表面积为30 m2·g-1、平均孔径为8.8 nm,是一种介孔催化剂,该催化剂在蒜头果油甲酯化实验中表现出高的催化活性,蒜头果油甲酯化率最高达到96.4%。
关键词: 镁铝复合氧化物  类水滑石  制备  蒜头果油  甲酯化
基金项目: 云南省林业科学院森林植物培育与开发利用重点实验室开放基金(No.2016-03)、国家自然科学基金(No.31670599)和云南省可再生能源发展专项资金(No.[2015]86)资助项目
Abstract: The catalytic performance of catalyst supported on the Al2O3-MgO was unstable due to the loss of aluminum ions caused by the excessive NaOH.In this study,a stable catalyst Na2O/Al2O3-MgO was synthesized using the ammonia as precipitator to generate co-precipitate of Mg-Al which it subsequently underwent impregnation with Na2CO3,aging process and calcination.In addition,the structure and morphology of the catalyst were characterized through XRD,SEM,SEM-EDS,TG-DSC,and N2 adsorption-desorption,and the catalytic activity was evaluated by the methyl esterification rate of malania oleifera oil.The results showed that catalyst precursors with the hydrotalcite-like structure could be obtained by co-precipitation and impregnation method,which the decomposition temperature of it was in the range of 200~500℃ and there were Na-Al as well as Na-Mg-Al oxides in the catalyst after high temperature calcination.The preparation condition of Na2O/Al2O3-MgO catalyst with high activity covered nMg/nAl as 3:1~1:3,the aging time as 12 hours,calcination temperature as 550℃ and calcination time as 5 hours.The verification experiment of catalyst prepared with nMg/nAl as 1:1 was conducted and the result revealed that the catalyst was a mesoporous catalyst with specific surface area of 30 m2·g-1 and the average pore size of 8.8 nm.Moreover,the catalyst processed high activity in the methyl esterification rate of malania oleifera oil and the conversion rate was up to 96.4%.
Keywords: magnesium-aluminum composite oxides  hydrotalcite-like compound  preparation  malania oleifera oil  methyl esterification
投稿时间:2016-10-07 修订日期:2017-05-12
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刘守庆,李雪梅,和献武,刘祥义,郑志锋.高活性固体碱Na2O/Al2O3-MgO的合成与表征[J].无机化学学报,2017,33(7):1153-1160.
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