INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Jian Zhang,Kai Shi,Zhe An,Yanru Zhu,Xin Shu,Hongyan Song,Xu Xiang,Jing He
Dehydrogenation coupling of ethanol to n-butanol has received much attention due to the wide application of n-butanol. Highly selective butanol production from ethanol remains a challenge due to competitive reactions in the dehydrogenation and/or condensation and great difficulty in ethanol dehydrogenation. This work reports a synergistic catalysis between layered double hydroxide (LDO), an acidic–basic support, and supported Ag particles for the dehydrogenation coupling of ethanol to n-butanol. A selectivity of up to 77% toward n-butanol with an ethanol conversion of 23.2%, among impressive levels reported till now, has been achieved at 350 °C, 0.1 MPa. A selectivity of up to 60% toward n-butanol with an ethanol conversion of 45%, the highest selectivity at an ethanol conversion of >45% reported till now, has been achieved at 250 °C, 2 MPa. A synergistic catalysis between the acid–base sites of the LDO surface and supported Ag particles have been revealed to contribute the excellent butanol selectivity: basic sites promote adsorption and subsequent dehydrogenation of ethanol on Ag particles; in addition to the promotion from Ag, the following aldol condensation is boosted by acid–base cooperation.
研究领域:
催化化学
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材料科学
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能源化学
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产品关联
DOI
高影响因子
Green Chemical Engineering
·
2021
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IF 0
Jiajun Wang,Zewei Liu,Shiye Li,Chaoping Li,Su Liu,Jingwen Feng,Rong Tan
Intramolecular acid-base cooperative catalysis is a powerful strategy to promote the nucleophilic additions in synthetic chemistry, since both substrates and nucleophiles can be activated simultaneously, yielding a lower energy reaction pathway. However, the systems often suffer from catalyst quenching due to the mutual neutralization of acid/base sites. Herein, we doped the boron (B) atoms in the tri- s -triazine ring of graphite-like carbon nitride ( g -C 3 N 4 ) framework, to develop the acid-base cooperative catalyst for nucleophilic addition. Characterization results demonstrated a foam-like hierarchical porous structure, as well as the coexistence of Lewis acid and base sites in the as-synthesized samples. As a result, the B-doped g -C 3 N 4 acted as the efficient acid-base cooperative catalysts, significantly promoting the Knoevenagel condensation whose key step involves in nucleophilic addition. A wide range of α, β-unsaturated carbonyl compounds with remarkably high yields (> 90%) was achieved even within 1 h in water, whereas the acid-free or base-free counterpart was far less efficient. In addition, the bifunctional catalysts exhibited excellent reusability with simple treatment. The novel B-doped g -C 3 N 4 catalytic system offers several advantages, such as operational simplicity, mild reaction conditions, high efficiency, and facile reuse of catalyst. All these advantages make it a benign protocol from the sustainability point of view, and inspired us to design the other bifunctional cooperative catalysts for a wide range of sustainable industrial applications.
研究领域:
材料化学
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催化化学
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DOI
CATALYSIS TODAY
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2022
·
IF 6.562
Hailong Xu,Miaomiao Chen,Min Ji
A series of highly-defective UiO-66 were synthesized and utilized as catalyst in the hydrogenation of cinnamaldehyde (CALD) to cinnamylalcohol (CALH) in isopropanol. The physico-chemical properties of the catalysts were characterized by powder X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis and N 2 adsorption-desorption. It was found that there are two kinds of atomic Lewis acid-base pairs existing in the defective UiO-66, exactly Zr 4+ -O 2- and Zr 4+ -OH - , which are active sites for CALD hydrogenation to form CALH. UiO-66–0.3 with the most defects shows a much higher reaction rate constant, which is 5.5 times that of UiO-66–2.0, and gives the best CALD conversion of 85.5% and CALH selectivity of 94.0% at 140 ℃ after 3 h. The acid-base synergistic catalysis mechanism was proposed. Moreover, the defective UiO-66 showed good recyclability for up to 7 cycles with retention of catalytic activity as well as structural stability.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
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IF 4.9
Lu Ren,Bin Wang,Yueli Wen,Maohong Fan,Zhaoxiong Huang,Wenxuan Li,Wei Huang,Jing Li,Jianping Guo
Acid-base synergistic effect is crucial in adjusting the catalytic performance of CO 2 hydrogenation to methanol, an efficient CO 2 emission reduction and carbon recycle strategy. Two MOFs-derived catalysts (CZ-MIL, CA-ZIF) with opposite acid-base properties were tailored by using MIL-68 (Al) and ZIF-8 (Zn) as precursors, and the above two MOFs precursors were hybridized (C-ZAx) to control the acid-base property of the catalyst. C-ZA0.6 (molar ratio of MIL-68 (Al) to ZIF-8 (Zn)=0.6) exhibits a promising catalytic performance with CO 2 conversion of 8.9 %, methanol selectivity of 61.85 %, and STY of 117.02 mg mL −1 ·h −1 at 4 MPa and 523 K. Combined with comprehensive analysis, it is found that methanol selectivity is closely related to weak acid sites arising from the residual skeleton of MIL-68. Acid-base synergy facilitates the hydrogenation of CO 2 to methanol. The basic sites are responsible for adsorbing and activating CO 2 , and the acidic site helps to stabilize CO* and facilitate the further hydrogenation to methanol. This work provides a new idea and feasible method for enhancing the catalytic performance of CO 2 hydrogenation to methanol.
研究领域:
催化化学
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材料科学
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环境科学
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产品关联
DOI
高影响因子
CATALYSIS TODAY
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2020
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IF 5.825
Hongqin Ma,Yanan Guan,Wenyao Chen,Zhijun Sui,Gang Qian,De Chen,Xinggui Zhou,Xuezhi Duan
In this work, the support effects on vapor-phase aldol condensation of methyl acetate (MeOAc) with formaldehyde (HCHO) over cesium catalysts are understood by the employment of Al 2 O 3 with different morphologies and crystal phases. The structural and electronic properties of these supported Cs catalysts are characterized by multiple techniques, such as XRD, HAADF-STEM, EDS-mapping, XPS, NH 3 -TPD and CO 2 -TPD. The Cs species are found to be highly dispersed on the Al 2 O 3 surfaces, and their compositions vary with the identity of Al 2 O 3 . A combined catalyst characterization and testing results indicates a balance between acidic and basic sites, i.e., an acid-base synergy, for the production of MA: the excess acidic sites lead to the lower MA selectivity due to the promoted further condensation, while the excess basic sites with the lower MeOAc conversion due to the insufficient activated HCHO species. These insights could be valuable for the design and optimization of catalysts for this reaction.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 10
·4245-4252
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IF 2.7
Jinfa Yu,Xiangying Sun
Carbon dots with good photoelectric properties are usually used as photocatalysts and electrocatalysts, but the good catalytic performance of carbon dots as nanomaterials for thermal catalysis is ignored. Herein, the application of novel efficient catalysts based on carbon dots for the transformation of carbon dioxide (CO2) to carbonates under solvent-free conditions is described. Carbon dots containing carboxyl, hydroxyl, and amine groups were prepared by a microwave technique and employed together with KI, which showed exceptional catalytic activity in the cycloaddition of carbon dioxide with different epoxides. In addition, the catalyst was easily reusable and had stable recyclability. And the catalyst displayed outstanding catalytic performance due to the synergistic effect of carboxyl (–COOH), hydroxyl (–OH), and amine (–NH) groups.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Meng Linghu,Yang Jiakun,Huo Zichen,Wu Qin,Zhang Yaoyuan,Shi Daxin,Chen Kangcheng,Liu Helei,Xu Xiyan,Li Hansheng,Xu Hang
The capture and transformation of CO 2 , utilized as a C1 resource, play an integral role in mitigating CO 2 emissions and addressing the emerging 'carbon source crisis.' The CO 2 cycloaddition to cyclic carbonate is particularly noteworthy. A critical factor in optimizing the efficiency and minimizing the costs associated with CO 2 cycloaddition is the selection of an effective catalyst. A novel amine-functionalized intramolecular acid-base synergistic ZIF catalyst, designated as ABF-ZIF-X, was synthesized using a mixed ligand method, employing 2-MeIM and the larger molecular-sized ligand 2-amBzIM. The introduction of an amino active center and the strategic regulation of the active site defects in metal ions enable ABF-ZIF-X to enhance the density of Lewis acid and base sites. This enhancement facilitates intramolecular acid-base cooperation, which is pivotal for effective CO 2 cycloaddition catalysis. Notably, ABF-ZIF-X exhibits exceptional catalytic activity in the cycloaddition of EBH with CO 2 , eliminating the need for additional solvents and co-catalysts. The reaction mechanism of CO 2 cycloaddition, which is intramolecular acid-base synergistic catalysis and bimolecular activation, was proposed. Among the synthesized catalysts. ABF-ZIF-0.15 shows superior performance, achieving an impressive 96.7% conversion of EBH and a selectivity of 97.1%. Furthermore, this catalyst demonstrates remarkable reusability, maintaining high activity across five cycles.
研究领域:
材料科学
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化学工程
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
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2025
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IF 4.2
Yong Pan,Chaoqin Ren,Jingshu Jin,Yanjun Wang,Sébastien Leveneur,Juncheng Jiang
Sustainable and renewable energy plays a key role in coping with the global energy crisis and increasing demand for development. Biomass valorization is regarded as a potential way to substitute the fossil raw materials in various fields such as electricity, fuel, chemicals, pharmaceuticals, etc. Among the numerous chemicals derived from biomass, γ-valerolactone (GVL) is identified to be an important platform chemical with wide applications. Hydrogenation of levulinic acid (LA) with formic acid (FA) as hydrogen donor for GVL production attracts great attention from the principle of green chemistry. Compared to the enormous efforts on catalyst design, few studies focus on the safety issues of this hydrogenation process, such as thermal runaway risk. Aiming to fill this gap, hydrogenation of LA with FA catalyzed by synthesized homogeneous catalyst Ru-TsDPEN was chosen as a typical efficient process for the production of GVL. In particular, solvent effect and acid-base synergetic effect by adjusting acid-base loading were investigated for process optimization and further calorimetry study. Apparent pH was measured to indicate the strength of acidity and alkalinity of the reaction mixture. Thermal stability of chemicals and thermal risk assessment were performed by differential scanning calorimetry and accelerated rate calorimeter Phi-Tec II, respectively. The results showed significant acid-base synergetic effect on the desired catalytic system and thermal risk was medium under the optimized condition, which needs specific safety measures for loss prevention. Suggestions for inherently safer chemical process for GVL production with FA as hydrogen donor were proposed.
研究领域:
化学工程
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可再生能源
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绿色化学
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产品关联
DOI
高影响因子
Science China-Chemistry
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2012
·Vol. 55
·期 6
·1167-1174
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IF 1.02
Lang WanZhong,Su Bo,Guo YaJun,Chu LianFeng
Four amine functionalized mesoporous catalysts were synthesized by grafting primary, dualistic and two secondary amines onto the channel walls of mesoporous silica, MCM-41. We examined the effects of organoamine loading amount on the acid-base synergism of the catalysts in the self-condensation reaction of n -butanal, a Knoevenagel condensation and a Henry reaction. We observed the balance of the amine and residual silanol amounts is crucial to the catalytic performances of the functionalized mesoporous catalysts. An optimum organoamine loading amount exists, which is dependent on the organoamine type. There is little difference in the optimum organoamine loading amount between different reactions. The secondary organoamine functionalized MCM-41 exhibits the best catalytic performance in the experimental range.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
POLYMER
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2022
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IF 4.432
Jianghuai Hu,Huanxin Xie,Zhengzhu Zhu,Wenjie Yang,Wei Tan,Ke Zeng,Gang Yang
High melting points (M p ) and high curing temperatures are two key processing problems that limit the application of aromatic cyano-based (AC) resins. A Brønsted acid-base synergistic strategy based on an acid-base eutectic and mechanisms for nucleophilic addition and ionization equilibrium are proposed to reduce the M p and curing temperature of AC resins. Blends of 4,5-dicyanoimidazole (DCI, Brønsted acid) and amine-containing phthalonitriles (4‐(4 or 2 or 3)‐aminophenoxy) phthalonitrile, APNs, Brønsted bases) were selected as model acid-base systems to study the synergistic behaviors in processing. The results show that the M p and the peak exothermic temperature (T rp ) of APN-DCI blends can be reduced by more than 31 °C and 85 °C compared with their intrinsic components, respectively. DSC and XRD show that the decrease in the Mp of the blends is induced by the formation of eutectics. A positive relationship between △pKa and the curing reactivity is confirmed by theory and experimental methods. The cured products show outstanding thermal and mechanical properties compared with reported AC resins. This research provides a new convenient route for regulating the curing behavior of AC resins and will significantly promote the development of high-performance AC resins.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 9
·2986-2993
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IF 5.721
Wenda Hu,Zixin Chi,Yan Wan,Shuai Wang,Jingdong Lin,Shaolong Wan,Yong Wang
This work presents a novel method to selectively convert levoglucosan to lactic acid (LA) via initially adding LA as the Brønsted acid together with modified Sn-β as the Lewis acid. Sn-β catalysts exchanged with various cations significantly enhance the yield of LA, following the order Sn-β < Sn-β–Na < Sn-β–K < Sn-β–Mg, Sn-β–Ca. The role of exchanged alkali ions stems from removing the remaining Brønsted acid sites in the zeolite and tuning the framework oxygen with more Lewis base sites. The exchange with alkaline earth cations such as Ca2+ and Mg2+ appears to be more effective in promoting the retro-aldol condensation due to the synergetic effect of their stronger Lewis acid that can stabilize the oxygen atom of deprotonated alkoxides during the reaction. The LA yield from levoglucosan can reach up to 66% on Sn-β–Ca under the optimized conditions. We also demonstrated that such a synergetic effect of alkaline-earth ion exchanged Sn-β shows great universality toward enhanced retro-aldol condensation, which can significantly promote the yield of methyl lactate over glucose conversion in methanol solvent.
研究领域:
催化化学
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生物质转化
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绿色化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yingyu Ren,Meng Zhang,Donghui Pang,Haisong Feng,Xin Zhang,Mingfei Shao,Chun Shen,Yusen Yang,Min Wei
Catalytic transfer hydrogenation (CTH) of aldehydes/ketones by using alcohols as hydrogen donors is an attractive and environmentally friendly hydrogenation technology, which has evoked widespread attention in synthesis of fine chemicals from biomass resources. In this work, a Co-Al mixed metal oxide catalyst (Co 1 Al 2 -MMO-200) was obtained through structural topological transformation process of layered double hydroxides, which was used in the CTH reaction of furfural with isopropanol. Notably, the reaction rate achieves 0.023 mol g −1 h −1 , which is preponderate to acid-base catalysts earlier reported. The joint research based on CO 2 -TPD, NH 3 -TPD and poisoning experiment substantiates that the synergy effect of acid-base sites plays an essential role in this catalytic system. Isotopic labelling MS, in-situ FT-IR and DFT studies further verify that the CTH reaction of furfural occurs via the Meerwein-Ponndorf-Verley (MPV) route, in which the basic site promotes the deprotonation of isopropanol whilst the acid site facilitates the formation of a six-membered ring transition state. This work demonstrates an acid-base synergetic catalysis for the CTH reaction by revealing the structure-property correlation and exploring reaction route, which is instructive for designing high-performance heterogenous catalysts.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）