Insights on Active Sites of CaAl-Hydrotalcite as a High-Performance Solid Base Catalyst toward Aldol Condensation
文献类型：期刊论文
| 作者 | Rao, DM; Xu, M; Zheng, LR ; Wang, B; Wang, YD; Wei, M; Zheng L(郑雷); Zheng LR(郑黎荣); Bing, WH; Zheng, L
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| 刊名 | ACS CATALYSIS
 |
| 出版日期 | 2018 |
| 卷号 | 8期号:1页码:656-664 |
| 关键词 | CaAl-hydrotalcite solid basic catalysts aldol condensation hydroxypivaldehyde structure-activity correlation |
| ISSN号 | 2155-5435 |
| DOI | 10.1021/acscatal.7b03022 |
| 文献子类 | Article |
| 英文摘要 | Solid base catalysts are highly demanded in many heterogeneous catalysis processes, but insights on active sites and structure-property correlation have rarely been revealed and remain a challenge. Herein, activated MxAl-layered double hydroxides (denoted as re-MxAl-LDH, M = Ca, Mg), as solid base catalysts toward the aldol condensation reaction, were prepared via a two-step procedure: calcination of the MxAl-LDH precursor to produce MxAl-mixed metal oxide (MxAl-MMO), followed by a further rehydration treatment. Structural characterizations confirm that re-CaxAl-LDH and re-MgxAl-LDH show similar morphology, particle size, specific surface area, and pore size distribution. However, a combination study including XPS, EXAFS, CDCl3-FTIR, and DFT calculations verifies that the host layer of re-CaxAl-LDH contains a distorted Ca(OH)(6) octahedron with an additional Ca-OH coordination that provides weak Bronsted basic site; in contrast, re-MgxAl-LDH consists of a Mg(OH)(6) octahedron structure accompanied by surface adsorbed hydroxyl group via noncovalent interaction, resulting in a medium Bronsted basic site. For the re-CaxAl-LDH samples, the concentration of weak Bronsted basic sites can be enhanced by tuning the Ca/Al molar ratio in the LDH precursor. The optimized re-CaxAl-LDH catalyst (re-Ca4Al-LDH) exhibits prominent catalytic performance toward the condensation of isobutyraldehyde (IBD) and formaldehyde (FA) to produce hydroxypivaldehyde (HPA), with a HPA yield of 61.5%. This is much higher than that of re-MgxAl-LDH (12.2%) and conventional solid base catalysts (4-33%), and even comparable to the level of liquid alkali (55-72%). Studies on the structure-property correlation reveal that the weak Bronsted basic site serves as active center to catalyze the aldol condensation, which accelerates the product desorption and largely promotes the HPA selectivity. |
| WOS关键词 | LAYERED DOUBLE HYDROXIDES ; ACETONE SELF-CONDENSATION ; FRIEDELS SALT ; MIXED-OXIDES ; WATER ; HYDROGENATION ; OXIDATION ; PHOSPHATE ; ALCOHOLS ; ALKANES |
| WOS研究方向 | Chemistry |
| 语种 | 英语 |
| WOS记录号 | WOS:000419751100067 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/285548]  |
| 专题 | 高能物理研究所_多学科研究中心 |
| 通讯作者 | Zheng LR(郑黎荣) |
| 作者单位 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | Rao, DM,Xu, M,Zheng, LR,et al. Insights on Active Sites of CaAl-Hydrotalcite as a High-Performance Solid Base Catalyst toward Aldol Condensation[J]. ACS CATALYSIS,2018,8(1):656-664. |
| APA | Rao, DM.,Xu, M.,Zheng, LR.,Wang, B.,Wang, YD.,...&He, S.(2018).Insights on Active Sites of CaAl-Hydrotalcite as a High-Performance Solid Base Catalyst toward Aldol Condensation.ACS CATALYSIS,8(1),656-664. |
| MLA | Rao, DM,et al."Insights on Active Sites of CaAl-Hydrotalcite as a High-Performance Solid Base Catalyst toward Aldol Condensation".ACS CATALYSIS 8.1(2018):656-664. |
入库方式： OAI收割
来源：高能物理研究所
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