DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 21
·7119-7128
·
IF 4
Zhengguo Zhang,Hongxiao Lv,Kun Yang,Xiutang Zhang
Developing materials with excellent properties has become the norm in the field of basic research, prompting us to explore highly robust hybrid materials based on electron-rich POMs and electron-deficient MOFs. Herein, a θ-[Mo8O26]4−-based hybrid material of [Cu2(BPPP)2]{θ-[Mo8O26]} (NUC-62) with excellent physicochemical stability was self-assembled under acidic solvothermal conditions from Na2MoO4 and CuCl2 in the presence of a designed chelated ligand of 1,3-bis(3-(2-pyridyl)pyrazol-1-yl)propane (BPPP), which has sufficient coordination sites, spatial self-regulation and great deformation ability. In NUC-62, each of two tetra-coordinated CuII ions and two BPPP are unified into one dinuclear unit serving as the cation, which is interactively linked to θ-[Mo8O26]4− anions via rich hydrogen bonds of C–H⋯O. Because of the unsaturated Lewis acidic CuII sites, NUC-62 exhibits high catalytic performance on the cycloaddition reactions of CO2 with epoxides under mild conditions with a high turnover number and turnover frequency. Furthermore, NUC-62, as a recyclable heterogeneous catalyst, shows high catalytic activity for the esterification of aromatic acid under refluxing, which is much better than the inorganic acid catalyst of H2SO4 in terms of turnover number and turnover frequency. Moreover, because of open metal sites and rich terminal oxygen atoms, NUC-62 shows high catalytic activity for Knoevenagel condensation reactions of aldehydes and malononitrile. Hence, this study lays the groundwork for constructing heterometallic cluster-based microporous MOFs with excellent Lewis acidic catalysis and chemical stability. Therefore, this study lays a foundation for the construction of functional polyoxometalate complexes.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
PubMed
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Haochuan Luo
An effective method to prepare crosslinked polybenzimidazole (PBI) via [2 + 3] Huisgen cycloadditions has been proposed. Propargyl modified PBI (PBI-PG) has been synthesized firstly. In the presence of diazido crosslinkers, PBI-PG can be thermally crosslinked by [2 + 3] Huisgen cycloadditions. Evidences from 1 H NMR and ATR spectra imply a small amount of grafting alkenyl structures on PBI-PG. The grafting alkenyl structures provide another crosslinking mechanism named as alkyne-alkene crosslink. The alkyne-alkene crosslink is highly efficient under heat to form crosslinking networks which display toughness, low tensile strengths, and large swelling ratios in phosphoric acid (PA) solutions. Influences of rigidities and chain lengths of crosslinkers on performances of crosslinked PBIs have been investigated. PBIs crosslinked by rigid crosslinkers behave as brittle materials while that crosslinked by flexible crosslinkers behave as tough materials. Addition of crosslinkers leads to decreased gel fractions but improved tensile strengths, which is attributed to competition results of crosslinking and plasticizing effects. PBI-R2-20, which is crosslinked by a long rigid crosslinker, exhibits the highest tensile strength of 102.33 MPa, which is 66.34 MPa higher than that of PBI-PG. With even lower PA uptakes, PBIs crosslinked by rigid crosslinkers display more thermally stable and higher conductivities than that crosslinked by flexible crosslinkers. After doping in 12 mol/L PA solution, PBI-R2-20, with an acid uptake of 163 wt%, displays the highest tensile strength of 8.1 MPa and the most thermally stable and the highest conductivity which reaches a maximum of 2.30 × 10 −2 S cm −1 at 188 °C among all crosslinked membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2020
·Vol. 53
·期 07
·1341-1348
·
IF 2.675
Xinxin Zhao,Lin Guo,Chao Yang,Wujiong Xia
A highly regioselective [3+2] cyclization of alkenes with 2-iodoanilines under the irradiation of UV light is described. This general, metal-free strategy facilitates the direct preparation of 2-mono-/disubstituted indolines as well as spiroindolines through alkene carboamination in one step. Mechanistic studies suggested that the photochemical protocol proceeded via a radical pathway.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Guangyao Zhai,Yuanyuan Liu,Yuyin Mao,Honggang Zhang,Lingtong Lin,Yujie Li,Zeyan Wang,Hefeng Cheng,Peng Wang,Zhaoke Zheng,Ying Dai,Baibiao Huang
CO 2 cycloaddition reaction from propylene oxide and CO 2 to cyclic carbonates is a desirable process to become carbon neutral. Photo energy can decrease the temperature and pressure needed for this reaction according to our previous results. However, the relationship between Lewis acidity and the photophysical process needs to be clarified and optimized. Hence, in this work, Zn is introduced into UiO-bpydc via the coordination of Zn with the bipyridyl group in bpydc. It is found that the introduction of Zn not only effectively activate propylene oxide, but also promote ligand to metal charge transfer (LMCT) process, which ultimately is beneficial for CO 2 activation. However, Ce plays a negative effect under light irradiation. namely, the presence of Ce facilitates the energy transfer process rather than the LMCT process.
研究领域:
材料科学
·
催化化学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Fangfang Li,Xiaofang Hou,Wei Fu,Jinjin Wang,Ying-Hua Zhou
The efficient transformation of CO 2 into high-value chemicals remains a significant challenge, particularly in the design of heterocatalysts capable of simultaneous multi-site activation towards the substrate. In this work, we develop the novel Zr-MOF catalysts incorporating both cobalt(II) meso-tetra(4-carboxyphenyl)porphine (CoTCPP) complex and the imidazolium bromide-based ionic liquid (IL) containing different alkyl chain (RImBr), where R = Et, Pr, Bu, and Pe), denoted as CoTCPP-UiO-66-IL(RImBr). The catalysts were synthesized through a solvothermal method followed by a post-synthetic modification. Among the prepared catalysts, CoTCPP-UiO-66-IL(BuImBr) demonstrated exceptional performance on the solventless and cocatalyst-free conversion of epichlorohydrin into chloropropene carbonate, achieving a remarkable 99% yield under mild conditions (90 °C and 1.0 bar CO 2 ). This outstanding catalytic efficiency was attributed to the synergistic effects of the dual Lewis-acid active sites offered by Zr-MOF node and the integrated CoTCPP complex, the strong nucleophilicity resulting from the incorporated imidazolium bromide-type IL, and the improved CO 2 adsorption capacity. Additionally, the CoTCPP-UiO-66-IL(BuImBr) catalyst exhibited excellent recyclability and broad substrate versatility in epoxide cycloaddition. These findings provide valuable insights into the development of multifunctional MOF-based heterogeneous catalysts with high activity and sustainability for CO 2 conversion applications.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Yongjian Wei,Ying Li,Yunfei Xu,Yuze Zu,Yinghui Sun,Tong Xu,Haiou Liang,Jie Bai
Exploring the impact of metal oxide crystal facets on the cycloaddition reaction of CO 2 with epoxides is meaningful because pure metal oxides exposing specific crystal facets show considerable promise as catalysts for industrial applications. In this study, we developed a simple strategy to prepare single-crystal ZnO nanosheet materials with controllable crystal facets through hydrothermal synthesis, followed by pyrolysis under different atmospheres. Studies revealed that the formation of ZnO single-crystal nanosheets involves the decomposition of the precursors and an ordered phase transition. Based on the quantitative correlation between oxygen vacancies, surface Zn, and the catalytic activity of ZnO (002) with varying numbers of oxygen vacancies, together with TPD, Py-IR, in-situ EPR, fluorescence spectroscopy characterizations, and DFT calculations, a synergistic mechanism between oxygen vacancies and surface Zn was proposed. Specifically, oxygen vacancies are the active sites for CO 2 , whereas saturated coordination surface Zn atoms activate epoxides. At 125 °C, 2 MPa, and 4 h, 93.3 % yield of the product was achieved using only 5 mg of the optimal ZnO catalyst. The excellent performance, stability, and applicability of single-crystal nanosheets make them ideal candidates for industrial applications. This study provides a new insight into the catalytic mechanisms of CO 2 cycloaddition over metal oxides.
研究领域:
材料科学
·
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2014
·Vol. 38
·期 7
·3078-3083
·
IF 3.159
Dan Kong,Yanyan Liu,Juan Zhang,Hongbian Li,Xiangyu Wang,Guangyu Liu,Baojun Li,Zheng Xu
The research on the heterogeneous catalytic synthesis of tetrazoles has attracted great attention. In this paper, a tungsten atom-containing AlPO-5 microporous molecular sieve (termed as WAlPO-5) was designed and synthesized by the incorporation of tungsten atoms into the AlPO-5 skeleton with triethylamine as a structure template from pseudoboehmite, H3PO4 and tungstophosphoric acid. The incorporation of tungsten atoms into the AlPO-5 skeleton has been demonstrated by systematic characterizations. WAlPO-5 can be used as an efficient heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles by [3+2] cycloaddition from nitriles and sodium azide. As a novel heterogeneous catalyst, WAlPO-5 exhibits a high catalytic activity, a superior cycling stability and an excellent substrate applicability. The significant advantages of WAlPO-5, such as the simple procedure and the mild reaction conditions and as an alternative to those corrosive, hazardous and polluting homogeneous catalysts, warrant its potential application in industrial processes.
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yi Liu,Ying Chen,Shuang Ma,Xianlong Liu,Xiangwen Zhang,Ji-Jun Zou,Lun Pan
High-energy–density (HED) fuels have attracted extensive attention for volume-fixed aerospace vehicles because they can provide more propulsion energy to increase the payload and range of aerospace vehicles. Herein, we report a route for synthesis of HED fuel, pentacyclo[8.2.1.1 4,7 .0 2,9 .0 3,8 ]tetradecane (PCTD) with strained structure, by photoinduced intermolecular [2 + 2] cycloaddition of norbornene (NBE). The triplet quenching and phosphorescence quenching results indicate that NBE cycloaddition is conducted through the photosensitized processes containing triplet–triplet energy transfer, cyclization and relaxation. The reaction conditions are optimized to obtain the high photocatalytic activity, with the NBE conversion and PCTD selectivity reaching 78.7% and 94.4%, respectively. Moreover, a kinetic model is proposed with the reaction rate equation being correlated with the incident light flux, with the pseudo reaction kinetics parameters and reaction rate equations obtained. Importantly, PCTD shows high density of 1.024 g/mL and high volumetric net heat of combustion of 42.98 MJ/L, much higher than those of JP-10. In addition, blending with JP-10 or QC can significantly improve cryogenic properties of blended fuels, which is very promising for the practical application.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2022
·
IF 5.907
Jiangtao Peng,Ruifeng Guo,Xiongxi Shi,Peiping Zhang,Fagui Qiu,Wenqing Li,Cundi Wei,Shiding Miao
A type of clay-supported catalysts was developed for cycloaddition of CO 2 by immobilizing metal-free ionic liquids (IL) on ball clay (BC) via a one-step strategy. The metal-free IL was loaded on the surface of BC via thermal and acid treatment. The synthesized materials (IL@P-BC) were characterized by Fourier transform infrared spectroscopy (FTIR), N 2 adsorption-desorption, and transmission electron microscopy (TEM). The composite IL@P-BC demonstrated excellent catalytic performance (yield 94.0%, selectively >99%) for coupling of CO 2 with epoxides to produce cyclic carbonates under the lack of any co-catalyst. The good recyclability and excellent suitability were obtained for the composite IL@P-BC. These experimental analyses deepen comprehension of the rational design of clay-based catalysts for CO 2 cycloaddition, further confirmed ball clay was a promising support.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 22
·7316-7325
·
IF 6.119
Chao Zhang,Hailian Bao,Xiaodi Chen,Xingliang Liu,Shiai Xu
Three typical arylamine organic dyes were covalently grafted onto g-C3N4 to form the resulting composites g-C3N4/TPA-CNCHO, g-C3N4/EtPTZ-CNCHO and g-C3N4/EtCz-CNCHO. They were synthesized by 1,3-dipolar cycloaddition with (E)-3-(4-(diphenylamino)phenyl)-2-formylacrylonitrile (TPA-CNCHO), (E)-3-(10-ethyl-10H-phenothiazine-3-yl)-2-formylacrylonitrile (EtPTZ-CNCHO), or (E)-3-(9-ethyl-9H-carbazol-3-yl)-2-formylacrylonitrile (EtCz-CNCHO) dyes. The experimental results show that arylamine organic dye moieties were successfully attached to g-C3N4, and this attachment can efficiently extend the light absorption area of pure g-C3N4 from approximately 460 nm to more than 650 nm. The obtained g-C3N4/TPA-CNCHO, g-C3N4/EtPTZ-CNCHO and g-C3N4/EtCz-CNCHO samples showed enhanced H2 evolution activity with photocatalytic H2 production rates that were approximately 105-, 93- and 67-fold that of pure g-C3N4. By combining the comprehensive analysis from experiments and density functional theory (DFT) calculations, a possible mechanism can be drawn: the introduced arylamine organic dye fragments attached to the surface of the g-C3N4 may acquire more light irradiation, and effective photoexcited carrier transfer from the donor dye fragments to the acceptor g-C3N4 could be achieved through the IFCT process. The results confirm that the covalent azomethine ylide bonds formed via 1,3-dipolar cycloaddition between the g-C3N4 and organic dye can truly enhance the photocatalytic H2 evolution rate of the obtained samples. It is believed that this kind of modification can be an effective strategy for achieving other kinds of functional organic dyes grafted onto g-C3N4 with highly efficient photocatalytic H2 activity.
研究领域:
材料科学
·
化学
·
光催化
·
能源材料
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2025
·
IF 3.3
Chaonan Wang,Kaixuan Guo,Zhonghan Cheng,Chongli Wang,Duozhen Chai,Dongfeng Cao,Ye Yuan,Somboon Chaemchuen
Metal-organic frameworks (MOFs) with ZIF-67 have been widely studied. Incorporating multi-bimetals into ZIF-67 offers a strategic approach to leverage unique properties and address the limitations of traditional single-metal in ZIF-67. An environmentally friendly solid-state thermal (SST) method to simultaneously incorporate heterometals (Cu, Fe, Ru, Pd, Mn, and Ni) into the ZIF structure, referred to as M@ZIF-67, is developed. The synthesis occurs in a single step, utilizing thermally-treated mixed solid precursors of multi-bimetals and imidazole ligands without additional agents or solvents, which is the innovative green route to approach multi-bimetals ZIFs. Multiple techniques confirm that heterometals are homogeneous, uniform, and precised metal content in the iso-structure of ZIF-67. Interestingly, synthesizing M@ZIF-67 through the SST method achieves a scalable and high yield. Furthermore, the M@ZIF-67 exhibits a precise heterometal content, which plays a crucial role in enhancing the catalytic performance of CO2 cycloaddition, surpassing results obtained through traditional ZIF-67.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Bin Jiang,Congcong Zhang,Na Yang,Qi Zhou,Longfei Zhang,Jingshuai Li,Wei Yang,Xiaodong Yang,Luhong Zhang
Developing highly active photocatalysts that can directly utilize clean, cheap, and sustainable solar energy to achieve an efficient carbon dioxide (CO2) cycloaddition reaction under mild reaction conditions (1 bar of CO2) remains a great challenge. In this paper, 2D/2D ZnIn2S4/Zn-NC S-scheme heterojunction composites were constructed by the in situ growth of layered ZnIn2S4 on the surface of two-dimensional (2D) ZIF-L-derived Znδ+ (0 ≤ δ ≤ 2) and N codoped carbon skeletons (Zn-NC-T) via a low-temperature solvothermal method. The optimized ZnIn2S4/Zn-NC-T photocatalysts exhibited favorable photocatalytic CO2 cycloaddition performance, and the yield of cyclic carbonate reached about 98.8% under 10 mmol epoxides reactant, 1 bar CO2 pressure, and full-spectrum irradiation for 4 h. The favorable photocatalytic performance is attributed to the efficient photothermal conversion and effective separation of photogenerated carriers induced by the carbon matrix and heterojunctions, respectively. In addition, the stability of the heterojunction structure and activity were demonstrated through cyclic experiments. Furthermore, the possible mechanism of S-scheme heterojunction photocatalytic CO2 cycloaddition is proposed through electron paramagnetic resonance (EPR) spectra, cyclic voltammetry (CV) experiments, and quenching experiments. The mechanism analysis proved that light irradiation is conducive to the transfer of photogenerated electrons from the conduction band of ZnIn2S4 to epoxides, promoting the formation of ring-opening intermediates, and photogenerated holes may promote the coordination and polarization of adsorbed epoxides. This work not only prepared an S-scheme heterojunction catalyst with excellent photocatalytic CO2 cycloaddition performance but also provided new insights for the rational design of heterojunction catalysts for photocatalytic CO2 cycloaddition.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 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）