JOURNAL OF CATALYSIS
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2025
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IF 6.5
Tianhao Zhang,Hanwen Yan,Chong Zhang,Yiqian Yang,Jie Li,Guoliang Zhang,Junping Zhang,Gang Wang,Chunshan Li
Effective strategy is intensively desired to construct efficient and durable catalytic system for mild aldol condensation between aldehydes, considering the profound significance in synthesis of high-valued α , β -unsaturated aldehydes. Although series of mild catalytic systems using secondary amine-based catalysts have been proposed, the compatibility of high catalytic selectivity and durability still troubles the researchers in this field. Here, we developed a protonated diethanolamine ionic liquid catalyzed mild aldol reaction system with reasonable regulation of ion pair strength and ionic cluster microenvironment based on the deep insights into proton shuttle effects to improve catalytic selectivity and durability for the probed methacrolein synthesis. The interplay between the cation and anion mediated proton shuttle was elucidated by detailed kinetics derived from in situ Raman spectroscopy and theoretical calculations. Further experimental and characterization facts combined with molecular dynamic simulations identify the weak interaction of cation–anion pair and metastable worm-like cluster microenvironment facilitate proton shuttle and thus improve catalytic performance and durability. Consequently, the formation rate of methacrolein was enhanced by one fold, while overall side reaction rates were reduced by 27.5% compared to the conventional sec -amine catalyst. Additionally, this strategy also exhibited significant promotion in catalytic activity, selectivity, and durability in synthesis of the other representative α , β -unsaturated aldehydes. These findings will offer reference for the construction and modulation of ionic liquid catalyzed mild aldol reaction system utilizing proton shuttle effects.
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
Joule
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2022
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IF 46.048
Yang-feng Cui,Yun-hai Zhu,Jia-yi Du,Yong-lai Zhang,Kai Li,Wan-qiang Liu,Gang Huang,Xin-bo Zhang
Rechargeable zinc-air batteries (ZABs) stand out among next-generation battery technologies due to their high energy density and high safety but suffer from electrochemical irreversibility. Herein, we report a hybrid ZAB with a long lifespan and high working voltage; it uses a neutral anolyte, an acidic catholyte, and a proton-shuttle-shielding dual-hydrophobic membrane to isolate the two electrolytes. The hybrid ZAB operates through the stable electrochemical plating and stripping of zinc (Zn) in a neutral anolyte and a high-voltage O 2 redox reaction in acidic catholyte. The designed proton-shuttle-shielding dual-hydrophobic membrane selectively transports hydrophobic bis(trifluoromethylsulfonyl)imide anions (TFSI − ) and effectively avoids the crossover of protons. As a result, the hybrid ZAB exhibits a high working voltage (1.50 V) and stable operation (up to 2,000.0 h) in ambient air. This strategy not only overcomes the severe irreversibility of conventional ZABs but also promotes development of electrolyte-decoupled systems.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
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2017
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IF 5.835
Hongxin Zhang,Shuangyan Hu,Junpeng Zhao,Guangzhao Zhang
Metal-free alternating copolymerization of 3,4-dihydrocoumarin (DHC) and ethylene oxide (EO) was realized by relatively mild phosphazene bases (t-BuP2 and t-BuP1), which unexpectedly outperformed previously employed t-BuP4 superbase in terms of polymerization rate, monomer conversion, and copolymer molar mass, though macrocycles were still generated when long chains were targeted. Such facts have indicated the occurrence of proton shuttling between phosphazenium cation and alkoxide which reduced chain-end nucleophilicity and thus alleviated side reactions such as backbiting. It was surprising that t-BuP1 whose basicity was too low for the homopolymerization of EO triggered alternating copolymerization, indicating that generation of anionic species (phenoxide) was essential for the epoxide-opening step. Well-defined short-chain diols were subjected to one-pot subsequent chain extension by addition of an aliphatic lactone or a diisocyanate leading to, respectively, block copolymer or polyurethane constituted by alternating segments. Poly(DHC-alt-EO) showed a better thermal stability than those of the substituted epoxides. This study has suggested that mild and non-nucleophilic organobases may be more suitable catalysts for epoxide-based metal-free alternating copolymerization toward well-defined macromolecular structures.
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Yunqiong Tang,Ting Zou,Zhiyu Su,Yinming Fan,Shengpeng Mo,Yanan Zhang,Dunqiu Wang,Yinian Zhu,Zongqiang Zhu,Xiaobin Zhou
Non-aqueous absorbents (NAAs) have emerged as promising candidates for CO 2 capture due to their energy-saving advantages and non-corrosive properties, yet necessitate further optimization in absorption capacity and regenerability for viable industrial implementation. This study developed a novel NAA through an innovative synergistic absorption–regeneration activation strategy, combining aminoethylethanolamine (AEEA) as the primary CO 2 -active component, 2-amino-2-methyl-1-propanol (AMP) to suppress insoluble products, with dimethylethanolamine (DMEA) and n-propanol (NPA) as dual-functional activators. Through coordinated activation mechanisms—DMEA-driven absorption enhancement and NPA-mediated regeneration promotion—the AEEA-AMP-DMEA-NPA (A-A-D-N) system achieved high-efficiency reversible CO 2 capture. Experimental optimization enabled A-A-D-N to obtain a CO 2 absorption loading of 1.51 mol·mol −1 (42.5 % higher than the DMEA-free system) and near-complete regeneration (≥98.13 %, 14.0 % improvement over the NPA-free system). The A-A-D-N formulation demonstrated exceptional cyclic stability, retaining the regeneration efficiency of 89.4 % after five consecutive absorption–desorption cycles. Mechanism studies combining 13 C NMR analysis and quantum chemical calculations revealed the dual-activation pathways: During absorption, DMEA facilitated zwitterion deprotonation and simultaneously regenerated active AEEA via AEEAH + deprotonation, enabling more AEEA to absorb CO 2 ; In regeneration, NPA acted as a proton shuttle through a low-energy-barrier relay mechanism, promoting efficient proton transfer from AEEAH + to AEEA-carbamate for carbamic acid formation, while subsequently catalyzing carbamic acid decomposition through proton exchange—a pathway distinct from conventional carbamate-to-carbonate conversion. Regeneration energy consumption analysis demonstrated A-A-D-N’s significant improvements over the benchmark 30 wt% MEA, with sensible heat and latent heat reduced by 76.1 % and 87.6 %, respectively. Furthermore, the A-A-D-N absorbent was verified to be non-corrosive to carbon steel. Overall, this work established a dual-activation strategy for developing novel NAAs with combined advantages of high-efficiency CO 2 capture capacity, energy savings and non-corrosive nature, thereby advancing CO 2 capture technologies.
研究领域:
化学工程
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环境科学
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材料科学
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物理化学
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能源技术
✓ 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）