INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2013
·
IF 1.233
Shun
Ping Wang,Xiao
Deng Yang,Qing
Quan Bai,Tian
Duo Li
A comparative kinetic study of the urethane reactions of phenyl isocyanate and 1,2-, 1,3-, and 1,4-butanediol was carried out in dichloromethane solution with zirconium (IV) acetylacetonate as catalyst. In situ FT-IR was used to follow the kinetics of the reactions at a constant temperature of 15°–30°C. The rate constants for the reaction of the primary hydroxyl group and the secondary hydroxyl group were calculated as k
prim and k
sec, respectively. Analysis of the second-order rate constants of these systems indicated that k
prim follows 1,2-butanediol >1,3-butanediol >1,4-butanediol. The ratio of k
prim/k
sec in 1,2-butanediol was the highest and the order followed was the same as with the reaction rate. Activation energies and Eyring parameters were also determined for the urethane reaction of butanediols.
研究领域:
化学
·
材料科学
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DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·915
·
IF 3.9
Xiaofeng Yu,Chunjie Shi,Yueling Cheng,Yejing Zhu,Renyuan Song,Shengfei Hu
Methyl benzoate (MB) compounds are prepared by reacting various benzoic acids with methanol using an acidic catalyst. In this study, the solid acids of zirconium metal solids fixed with various substances were studied. We determined that zirconium metal catalysts with fixed Ti had the best activity. The catalytic synthesis of a series of MB compounds using titanium zirconium solid acids was studied. The direct condensation of benzoic acid and methanol using a metallic Lewis acid without other auxiliary Bronsted acids is reported for the first time.Keywords:methyl benzoate;solid acid;catalysis
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
GREEN CHEMISTRY
·
2017
·Vol. 19
·期 20
·4829-4837
·
IF 9.125
Yufei Sha,Zhenhuan Xiao,Huacong Zhou,Keli Yang,Yinmin Song,Na Li,Runxia He,Keduan Zhi,Quansheng Liu
With the increasing demands for energy and carbon resources, exploration of novel utilization approaches of fossil resources and promotion of the conversion of sustainable resources become critical issues facing human society. In this study, we used humic acids (HAs), which are important derivatives from the low-rank coal, and the transition metal zirconium (Zr) to construct novel Zr-containing catalysts (Zr-HAs) for Meerwein–Ponndorf–Verley (MPV) reactions of biomass-derived platforms. Both commercial HAs and HAs extracted directly from lignite without any purification were used as raw materials to prepare the catalysts. The results showed that Zr-HAs catalysts were highly efficient for the conversion of furfural, with a high furfuryl alcohol yield of up to 97%, and also effective for the conversion of other carbonyl compounds with different structures under mild conditions. This novel strategy to construct catalysts using HAs as raw materials may be beneficial for both value-added utilization of low-rank coal and the conversion of biomass resources.
研究领域:
能源化学
·
催化化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Biao Zhao,Yong Men,Anni Zhang,Jinguo Wang,Rong He,Wei An,Shenxiao Li
The effects of zinc precursors on the performance of bifunctinal Zn 1 Zr 10 O x catalysts were investigated for direct conversion of bio-ethanol into isobutene (ETIB). The catalyst derived from zinc acetate precursor exhibited full ethanol conversion and 50% isobutene yield at a WHSV of 0.38 g ethanol g cat −1 h −1 at 450 °C. Characterization results based on XRD, FT-IR, UV–vis, Raman, BET, CO 2 -TPD, NH 3 -TPD, H 2 -TPR, and XPS revealed that Zn 1 Zr 10 O x catalyst prepared by zinc acetate precursor with large anion size possessed the highest zinc dispersion and the strong ZnO-ZrO 2 interaction, and presented the highest ethanol reaction rate and isobutene yield under kinetic control regime. The beneficial effect of larger anion size was rationalized by the shielding effect in the incorporation model dominated by the size of capping anion in zinc precursors. Further durability test showed that the catalyst exhibited slow deactivation against coking formation while isobutene yield was maintained above 45% for 18 h.
研究领域:
化学工程
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催化科学
·
材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 10
·2624-2635
·
IF 5.365
Jingxia Tian,Wei Chen,Peng Wu,Zhirong Zhu,Xiaohong Li
A Cux–Mgy–Zrz/SiO2 catalyst with a total metal loading of 60 wt% prepared by a deposition–precipitation method was applied for the selective hydrogenation of ethylene carbonate to methanol and ethylene glycol in a fixed-bed reactor. As a result, the Cu8–Mg1–Zr0.47/SiO2 catalyst furnished 99% ethylene carbonate conversion with 85% selectivity to methanol and 99% selectivity to ethylene glycol under the optimized reaction conditions. Moreover, the Cu8–Mg1–Zr0.47/SiO2 catalyst also showed a good lifetime and neither the activity nor the selectivity decreased the during 208 h test. The reaction was found to depend sensitively on the Cu particle size, the surface acidity and the catalyst surface composition. The synergistic effect of balanced Cu0 and Cu+ sites was considered to play a critical role in attaining high yields of methanol and ethylene glycol. Boric oxide also had a positive effect on the hydrogenation of ethylene carbonate, affording higher selectivity to methanol under much milder conditions.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Lanlan Shi,Feike Zhang,Xiaojun Wang,Jingxian Li,Yuanming Liu,Weijie Fu,Shuyun Yao,Shiyu Wang,Kang Ji,Yingjie Ji,Zhiyu Yang,Jiangzhou Xie,Yi-Ming Yan
Improving the electrocatalytic conversion of formate in alkaline solutions is crucial for the commercial application of formate fuel cells. However, palladium-based catalysts used for formate oxidation reactions (FOR) face challenges due to the strong adsorption of hydrogen intermediates, resulting in lower catalytic efficiency in alkaline environments. Herein, we prepared a PdZr/C catalyst aimed at employing a doping-induced strain strategy to reduce the hydrogen binding energy of palladium and release more active sites for the oxidation of formate. Through density functional theory calculations and experimental investigations, we find that the lattice compression induced by Zr doping regulates the electronic structure of Pd. Specifically, the incorporation of Zr dopant shifts the d-band center of Pd downward, weakening the binding energy of hydrogen at the Pd sites. This adjustment promotes the desorption of hydrogen intermediates, thus accelerating the FOR kinetics by alleviating the site-blocking effect. As a result, the PdZr/C catalyst exhibited a 2.4-fold increase in activity compared to the conventional Pd/C catalyst. It also achieved a lower peak potential and delivered a significantly higher peak current of 1917 mA mg–1. These findings highlight the critical role of lattice strain in tuning the catalytic properties of Pd and offer valuable insights into the design of high-performance electrocatalysts for energy conversion technologies.
研究领域:
材料科学
·
催化化学
·
能源转换技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Xiaoxiao Zheng,Xiaoping Chen,Xiaoqing Li,Jide Zhu,Jipeng Chen,Fengcai Lin,Lijuan Shen,Yanlian Xu,Lilong Jiang
The development of stable and effective catalysts to convert toxic H2S into high value-added sulfur is essential for production safety and environmental protection. However, the inherent defects of traditional iron- and zirconium-based catalysts, such as poor activity, high oxygen consumption, and low sulfur selectivity, limit their further developments and applications. Herein, the Fe–Zr bimetallic organic framework FeUIO-66(x) with different cubic morphologies was synthesized via a facile solvothermal method. The results indicate that the introduction of Fe not only increases the specific surface area and weak L-sites of the catalyst without changing its crystal structure, which provides enough reaction space and more active sites for the adsorption and activation of H2S, but also reduces the activation energy of the reaction, significantly promoting the selective oxidation of H2S. As a result, the as-obtained FeUIO-66(1) catalyst exhibits the highest desulfurization activity and superior durability and water resistance stability, and its H2S conversion and sulfur selectivity within 50 h are 100 and 88%, respectively. More importantly, the structure of the catalyst after the desulfurization reaction is consistent with that of the fresh counterpart. The study offers new insights into the development of effective and stable bimetallic catalysts to eliminate H2S and recycle sulfur.
研究领域:
催化化学
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环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2017
·Vol. 32
·期 3
·e4177
·
IF 2.319
Shaohua Wen,Yongfei Li,Weixing Chen,Yaping Lei,Chunyan Luo,Yonggang Hou
A series of L-lactide (LLA), 1,3-trimethylene carbonate (TMC) and glycolide (GA) terpolymers (LTG) of different monomer molar ratios were synthesized by using ring-opening copolymerization. An effective and low-toxic zirconium (IV) acetylacetonate Zr(Acac) 4 was used as catalyst. The viscosity-average molecular weights ( M η ) of obtained polymers were all above 2.2×10 4 g/mol. The chemical structure and viscosity of terpolymers were confirmed by Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance ( 1 HNMR), 13 C nuclear magnetic resonance ( 13 CNMR) and an Ubbelohde viscometer. The thermal and mechanical properties were investigated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and stress-strain measurements. Results suggested that all terpolymers were amorphous and showed good thermal stability. Also it was found that elongation increased with the decreasing of LLA unit. More importantly, terpolymers displayed shape memory property when deformation temperatures were 14-15 °C above T g .
研究领域:
高分子化学
·
材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 22
·6782-6794
·
IF 6.177
Yuxi Xu,Huijiang Huang,Lingxin Kong,Xinbin Ma
Copper–zirconium catalysts have been extensively applied in the hydrogenation of carbon–oxygen bonds such as in CO2 and esters. However, high-performance Cu/ZrO2 catalysts with low copper loading for dimethyl oxalate (DMO) hydrogenation to ethylene glycol (EG) are seldom reported. Herein, we fabricated 5 wt% Cu/ZrO2 catalysts by a co-precipitation method and investigated the effect of calcination temperature on the catalyst structure and the corresponding catalytic performance. The crystallization and migration of zirconium and copper species are not simultaneous when increasing the calcination temperature, so the elemental composition of Cu and Zr species is different on the surface and in the bulk CuZrO2 solid solution. The crystalline morphology of ZrO2 is transformed from a-ZrO2 to t-ZrO2 and m-ZrO2 and copper dispersion is also changed. The CZ-600 catalyst has the largest copper dispersion, surface area of Cu0 and Cu+ and strongest H2 adsorption ability, which endow this catalyst with the best catalytic performance. However, TOF values are the largest for the CZ-550 catalyst with a larger ratio of Cu+, oxygen vacancies and Zr3+, which suggests the interfacial synergy between Cu and ZrO2 in DMO hydrogenation. And further increasing the calcination temperature to above 700 °C will cause the aggregation and sintering of copper nanoparticles and deteriorate the hydrogenation reactivity.
研究领域:
催化化学
·
材料科学
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DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 11
·期 3
·810-822
·
IF 5.721
Shipeng Wu,Hao Zhang,Qiue Cao,Qihua Zhao,Wenhao Fang
Direct oxidative coupling of alcohols with amines using a non-precious metal oxide catalyst under mild conditions is highly desirable for imine synthesis. In this work, a mesoporous Mn1ZrxOy solid solution catalyst prepared by a co-precipitation method showed excellent catalytic performance in imine synthesis from primary alcohols and amines without base additives in an air atmosphere. XRD, N2 physisorption, H2-TPR, O2-TPD, EPR and XPS were comprehensively used to unravel its structural, redox and amphoteric properties that closely depended on the interaction between MnOy and ZrO2 with a variable Zr ratio. The Mn1Zr0.5Oy catalyst presented the highest fractions of Mn3+ ions and reactive oxygen species on the surface, and the highest concentrations of acidic–basic sites, which were disclosed to play important roles in activating alcohols and molecular O2 in the rate-determining step. In the model reaction of oxidative coupling of benzyl alcohol with aniline, such enhanced features of the Mn1Zr0.5Oy catalyst can promote the intrinsic catalytic activity (iTOF of 1.87 h−1) and boost benzylideneaniline formation (5.56 mmol gcat.−1 h−1) based on a >99% yield at 80 °C respectively at a fast response. It can also work effectively at a room temperature of 30 °C, as well as for the gram-grade synthesis. This is one of the best results among all the MnOy-based catalysts in the literature. Moreover, this catalyst showed good stability and a wide substrate scope with good to excellent yields of imines.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
ChemPlusChem
·
2015
·Vol. 81
·期 1
·135-142
·
IF 3.026
Hu Li,Zhen Fang,Song Yang
Graphical Attractive separation : Acid–base bifunctional NiZr nanocatalysts with strong magnetism show high activity and reusability in the transformation of biomass derivatives, including EL, fructose, glucose, cellobiose, and carboxymethyl cellulose, into γ -valerolactone (GVL) with 95.2 % yield and 98 % selectivity (see figure). A series of mixed oxide nanoparticles were prepared by a coprecipitation method and characterized by many techniques. Nickel–zirconium oxide catalysts and their partially reduced magnetic counterparts were highly efficient in the direct transformation of biomass derivatives, including ethyl levulinate, fructose, glucose, cellobiose, and carboxymethyl cellulose, into γ-valerolactone (GVL) without the use of an external hydrogen source, producing a maximum GVL yield of 95.2 % at 200 °C for 3 h with hydrogen-reduced magnetic Zr 5 Ni 5 nanoparticles (<20 nm). The acid–base bifunctionality of these nanocatalysts plays a synergic role in the synthesis of GVL in alcohols, whereas appropriate control of the nickel/zirconium molar ratio is able to improve the selectivity towards GVL (≈98 %), along with high formation rates (up to 54.9 mmol g −1 h −1 ). Moreover, the magnetic Zr 5 Ni 5 nanoparticles were conveniently recovered by means of a magnet for five cycles with almost constant activity.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Mian Hu,Jiayi Zheng,Zhiheng Ye,Yufan Jin,Xinyu Pan,Jiahui Huang,Yage Zhang,Junliang Wang,Zhong-Ting Hu,Zhiyan Pan
Traditional approaches for wastewater treatment in chemical industry primarily emphasize the degradation of organic pollutants, resulting in excessive waste of carbon resources and carbon oxide emissions. This work studied on subcritical catalytic water oxidation for conversion N,N-Dimethylacetamide (DMAC), a significant organic polar solvent and extensively utilized in the chemical industry, into acetic acid. In the presence of zirconia catalyst, the parameter factors such as different crystalline forms of ZrO 2 , reaction temperatures, residence times, oxidation coefficient (O/C), and alkaline additives on the degradation efficiency of DMAC and the corresponding product distribution and acetic acid selectivity were examined and optimized systematically. Under a condition of 320 °C, 30 min, O/C = 1, NaOH = 50 mmol/L, and t -ZrO 2 = 5 wt%, the DMAC conversation rate reached 98.00 % with acetic acid yield of 37.25 % (selectivity of 93.97 %). In addition, the carbon balance of all intermediates was analyzed, and conformed that the carbon originating from DMAC was mainly converted into CO 2 and acetic acid. This work provides a new strategy on efficient conversion waste carbon resources into chemical product of organic acid, which is significantly contributed to carbon emission reduction worldwide.
研究领域:
环境科学
·
化学工程
·
催化反应
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）