新型磷酸二氢铝镓金属无机骨架结构的合成及其催化乙醛制备丁醇醛的研究
Synthesis of Novel Aluminum Gallium Dihydrogen Phosphate Metal-Inorganic Framework and Its Catalytic Preparation of Butanolal from Acetaldehyde
曹宇鹏 1张汉杰 1黄继庆 1郭伟 1公绪滨 1方涛1
作者信息
- 1. 北京航天试验技术研究所,航天绿色推进剂研究与应用北京市重点实验室,北京 100074
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摘要
通过水热法制备了一种新型磷酸二氢铝镓(GAHPO)金属无机骨架结构,并通过单晶XRD、粉末XRD、红外,以及TG-DSC等分析手段对其进行充分表征.单晶XRD解析表明,该晶体属于三方晶系、Rc3空间群.Al(Ga)O6八面体与PO4四面体结构交替连接形成一维链状金属骨架,并由氢键堆叠成三维金属无机骨架结构.TG-DSC分析显示,GAHPO热稳定性良好,初始分解温度达到240℃.相比磷酸铝,Ga3+的引入使磷酸铝晶格畸变,削弱了Al—O的强度,增大了Al—O键长,使更多酸性位点暴露,从而提高GAHPO的催化活性.实验结果表明,反应温度在60℃,催化剂用量为10%时,GAHPO催化乙醛缩合制备丁醇醛具有良好的转化率(47%)和优异的选择性(>99%).酸/碱中和催化剂、NH3-TPD,以及大位阻基团取代乙醛反应位点的实验验证了GAHPO的催化乙醛缩合的反应机理.本工作为新型铝基无机骨架结构及其催化应用提供了可行途径.
Abstract
Here,a novel aluminum-gallium-phosphate(GAHPO)metal-inorganic framework structure was prepared by hydrothermal method,and it was fully characterized by single crystal X-ray diffraction,powder X-ray diffraction,IR spectroscopy,and gravimetric analysis-differential scanning calorimeter(TG-DSC).Single crystal X-ray diffraction results show that GAHPO is attributed to the trigonal system and Rc3 space group.Al(Ga)O6 octahedra and PO4 tetrahedral structures is distorted to form one-dimensional chains,and then is stacked into three-dimensional metal-inorganic frameworks through hydrogen bonding.TG-DSC shows that GAHPO is of high thermal stability,with the initial decomposition temperature of 240 ℃.Compared with aluminum phosphate,the introduction of Ga3+distorted the AlPO4 lattice,thus weakening and elongating the Al—O bond,which makes more acid catalytic sites exposed and enhanced the catalytic activity.The experiment shows that when the reaction temperature is 60 ℃,and the catalyst dosage is 10%of acetaldehyde,GAHPO could catalyze the condensation of acetaldehyde to produce butanolal with good conversion rate(47%)and excellent selectivity(>99%).The reaction mechanism of acetaldehyde condensation catalyzed by GAHPO was investigated using scavengers,NH3-TPD and specially designed derivatives to confirm the reactive sites of the catalyst and the substrate.This work provides a feasible way for novel aluminum inorganic framework structures and the catalytic applications.
关键词
磷酸二氢铝镓/水热合成/金属无机骨架/晶格畸变/催化/羟醛缩合Key words
aluminum-gallium-phosphate/hydrothermal synthesis/metal-inorganic framework/lattice distortion/catalysis/aldol condensation引用本文复制引用
出版年
2024