INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 20
·12679
·
IF 6.208
Miaomiao Zhang,Hongmei Jiao,Haojie Ma,Ran Li,Bo Han,Yuqi Zhang,Jijiang Wang
An operationally convenient Zn-catalyzed synthesis of alcohols by the reduction of aldehydes, ketones, andα,β-unsaturated aldehydes/ketones is reported. It is a rare example of using mild and sustainable HBpin as a reductant for catalytic reduction of carbonyl compounds in the absence of acid or base as hydrolysis reagent. The reaction is upscalable and proceeds in high selectivity without the formation of boronate ester by-products, and tolerates sensitive functionalities, such as iodo, bromo, chloro, fluoro, nitro, trifluoromethyl, aminomethyl, alkynyl, and amide. The Zn(OAc)2/HBpin combination has been also proved to be chemoselective for the C=N reduction of imine analogs.Keywords:zinc;reduction;aldehydes;ketones;imines
研究领域:
有机化学
·
合成化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yong-Bo Liu,Li-Mei Peng,Rui-Ying Bao,Ming-Bo Yang,Wei Yang
Because of its rather low melt strength, polylactide (PLA) has yet to fulfill its promise as advanced biobased and biodegradable foams to replace fossil-based polymer foams. In this work, PLA vitrimers were prepared by two-step reactive processing from commercial PLA thermoplastics, glycerol, and diphenylmethane diisocyanate (MDI) using Zn(II)-catalyzed addition and transesterification chemistry. The transesterification reaction of PLA and glycerol occurs with zinc acetate as the catalyst, and chain scission will take place due to the alcoholysis of the PLA chains by the free hydroxyl groups from the glycerol. Long-chain PLA with hydroxyl groups can be obtained and then cross-linked with MDI. Rheological analysis shows that the formed cross-linked network can significantly improve melt strength and promote strain hardening under extensional flow. PLA vitrimers still maintain the ability of thermoplastic processing via extrusion and compression. The enhanced melt strength and the rearrangement of network topology facilitate the foaming processing. An expansion ratio as large as 49.2-fold and microcellular foam with a uniform cell morphology can be obtained for PLA vitrimers with a gel fraction of 51.8% through a supercritical carbon dioxide foaming technique. This work provides a new way with the scale-up possibility to enhance the melt strength of PLA, and the broadened range of PLA applicability brought by PLA vitrimers is truly valuable in terms of the realization of a sustainable society.
研究领域:
材料科学
·
化学工程
·
可持续发展
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Jinrong Liang,Kejia Wu,Fukun Li,Jinxing Long,Qiang Zeng,Xuehui Li
Catalytic hydrogenolysis of the renewable aromatic polymer of lignin to value-added fine chemicals without external molecular hydrogen is of great significance. In this work, catalytic conversion of lignin with in situ H 2 produced from the aqueous phase reforming (APR) of methanol is studied in the presence of ZnO-modified Pd/AC (Pd-Zn/AC). 259.8 mg g -1 yield of monophenols is obtained when the lignin depolymerization is catalyzed by Pd-Zn/AC-10 in a methanol aqueous solution ( V C H 3 OH / V H 2 O =9/1) at 250 °C for 4 h. Extensive analysis showed that this effective process should be attributed to the synergistic effect between Pd-Zn alloy and the metallic Pd, which promote the H 2 production from the APR of methanol and the hydrogenolysis of lignin, respectively. Moreover, a plausible pathway for selective hydrogenolysis of lignin is proposed based on the comparative characterization of the raw lignin, residual lignin, and the transformation behavior of lignin model compounds.
研究领域:
化学工程
·
可再生资源化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xin Liu,Yong-De Yan,Yun Xue,Yue-Lin Wang,Qing-Guo Zhang,Guan-Qing Hu,Fu-Qiu Ma,Jing-Ping Wang
Waste resins produced from nuclear facilities operation always contain organic sulfur and radioisotope 65 Zn, which pose a significant threat for the ecological environment. This study proposed comparative research for treating cation exchange resins doped with Zn 2+ (Zn-CERs) in Na 2 CO 3 -K 2 CO 3 and Na 2 CO 3 -K 2 CO 3 -KOH. The enhanced removal effect of sulfur and Zn 2+ by KOH addition was explored. The energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were carried out to investigate the element distribution and chemical states of C, O, S and Zn on Zn-CERs. The results of thermogravimetric analysis (TG) showed that the oxidation process of Zn-CERs was basically divided into three steps, and Zn 2+ acted as a catalyst for S-C destruction. The relatively mild reaction of Zn-CERs in Na 2 CO 3 -K 2 CO 3 -KOH largely avoids the escape of harmful gases (H 2 S and SO 2 ) caused by the overreaction. The participation of KOH could promote the sulfation of sulfides and sulfites, and the transformational SO 4 2− content reaches a maximum value (26.51 %) at 800 °C. When the temperatures above 700 °C, Zn 2+ and K + combines with SO 4 2− to form K 2 Zn 2 (SO 4 ) 3 . The proposed enhanced molten salt oxidation (MSO) system had excellent retention rates of Zn (99.56 %) and S (87.39 %) at 800 °C, which provides further technical references for the removal of organic sulfur and heavy metals.
研究领域:
环境科学
·
核化学与放射化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Yulong Wu,Yingfang Nie,Li Sun,ZhenHao Xi,Zhen Liu
Zinc glutarate (ZnGA) is a prominent catalyst for the production of CO 2 -based poly(propylene carbonate). The original catalysts, ZnO-GA ( Cat 1 ) and ZnAc 2 -GA ( Cat 3 ), were prepared using ZnO and ZnAc 2 as Zn sources, respectively. ZnO-GA-H 2 O ( Cat 2 ) and ZnAc 2 -GA-H 2 O ( Cat 4 ) were prepared by water treatment of Cat 1 and Cat 3 , respectively. After water treatment, both Cat 2 and Cat 4 showed enhanced performance for copolymerization of CO 2 and propylene oxide. The characterizations demonstrated that H 2 O is a critical component that not only improves the crystallinity and external surface area of ZnGA, but also increases the number of surface Zn-OH groups. By adding a portion of cyanide, further modification on Cat 4 resulted in a group of ZnAc 2 -GA-H 2 O/DMC catalysts ( m-Cat 4 ). The polymerization reached a high yield of 1729 g poly/g Cat and a selectivity of 98.7 % at molar ratio of DMC/ZnGA = 1: 10 ( t = 24 h; T = 70 °C; P = 4 MPa). The modified ZnGA/DMC catalyst exhibited remarkable yield and selectivity for the copolymerization of CO 2 and propylene oxide to produce high molecular weight alternating copolymers (2.3 × 10 5 g/mol).
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2018
·
IF 3.463
Qinqin Wang,Mingyuan Zhu,Haiyang Zhang,Caixia Xu,Bin Dai,Jinli Zhang
Zr-modified ZSM-5 zeolite was successfully prepared, and Zn/Zr-ZSM-5 was employed as a catalyst for the acetylene hydration reaction. High catalytic activity, above 96% C 2 H 2 conversion, was achieved at 260 °C with a feed reactant ratio of H 2 O/C 2 H 4 = 4 and a GHSV of 90 h −1 . To understand the influence of zirconium addition in the zeolite, Fourier-transform infrared spectroscopy, X-ray diffraction, surface texture analysis (BET method), transmission electron microscopy, temperature programmed desorption of NH 3 , temperature programmed reduction by hydrogen and X-ray photoelectron spectroscopy techniques were used. The incorporation of zirconium in the zeolite enhanced Zn metal dispersion and metal–support interactions. Moreover, an enhanced concentration of weak acid sites and active catalytic sites were found to be responsible for the high catalytic activity of Zn/Zr-ZSM-5 for the acetylene hydration.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2016
·Vol. 227
·期 10
·1-8
·
IF 1.551
Li Ying,Yang Lijiao,Chen Cheng,Lan Yeqing
In this paper, Zn(0)-catalyzed ozonation degradation of acid orange 7 (AO7) and its impact factors including solution pH, Zn loading, and AO7 initial concentration were investigated through a series of bath experiments. The results demonstrated that Zn could markedly accelerate the degradation of AO7 by ozone (O 3 ) and the degradation efficiency of AO7 increased by 77 and 71 % within 30 min as compared with those in the systems of O 3 alone and Zn/air, respectively. The reuse of Zn resulted in a slight decline in AO7 degradation, suggesting that a coating of ZnO on the surface of Zn particles weakened Zn catalytic activity. The optimal removal of AO7 was achieved in a wide pH range of 4 to 10, and a lower or higher pH was not conducive to the degradation of AO7. In addition, the degradation efficiency of AO7 increased with Zn loading but decreased with AO7 initial concentration. The introduction of free radical scavengers into the system of AO7/Zn/O 3 confirmed that O 2
•− , rather than •OH, was the main free radicals responsible for the rapid removal of AO7. The degradation of AO7 by O 3 assisted with Zn could be well expressed with pseudo-first-order kinetic model.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Liuxin Xu,Xiaolin Tai,Lei Feng,Xu Zhang,Ya Pan,Bing Tang,Ruichao Xu,Yanna Shui,Jinglin Yuan,Yue Lin,Xiaolong Zhang,Shi He,Zhihu Sun,Shiqiang Wei
Propane dehydrogenation (PDH) using platinum-based intermetallic catalysts is an important approach for the industrial production of highly value-added propylene. Nevertheless, the high temperature needed for PDH inevitably causes deactivation of the intermetallic catalysts due to phase separation or particle aggregation. Herein, we showcase that a Pt shell offers a promising solution to protect intermetallics under harsh PDH environments. Through selective removal of the surface Zn atoms, a core/shell architecture with 1–2 atomic layers of Pt coating PtZn intermetallic nanoclusters is constructed. No deactivation was observed within an 80 h long-term stability test at 580 °C on the optimal PtZn/Pt catalyst, affording an extremely low deactivation rate constant of 0.0007 h–1. Furthermore, the construction of the PtZn/Pt core/shell promotes the catalytic efficiency, with a high propylene formation rate of 124.8 mol of C3H6 gPt–1 h–1 that surpasses that of most of the Pt-based PDH catalysts reported. Density functional theory calculations reveal that the Pt shell plays dual roles in stabilizing the intermetallic core and modifying the electronic structure of the ensemble by inducing a compressive strain. This lattice strain downshifts the d-band center to a lower value of −3.02 eV and decreases propylene desorption energy to a level lower than the barrier energy of C–H breaking by 0.66 eV, resulting in enhanced coking resistance and reactivity.
研究领域:
催化化学
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材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Zhi-Xin Li,Xian-Yong Wei,Guang-Hui Liu,Xing-Long Meng,Zheng Yang,Shuo Niu,Di Zhang,Hua-Shuai Gao,Zhi-Hao Ma,Zhi-Min Zong
Highly selective hydrogenation of furfural and levulinic acid (LA) was studied over Ni 0.09 Zn/NC 600 derived from zeolitic imidazolate frameworks. The existence of active Ni 3 ZnC 0.7 particles in Ni 0.09 Zn/NC 600 was confirmed by multiple characterizations. As a result, over Ni 0.09 Zn/NC 600 , 99.7% of furfural conversion (FC) and 100% of furan-2-ylmethanol selectivity (FMS) were achieved in isopropanol (IP) at 170 °C for 2 h, while FC and (tetrahydrofuran-2-yl)methanol (THFM) selectivity are 97.5% and 86.4% in water at 150 °C for 1 h. Over the same catalyst, LA was completely converted to γ-valerolactone in water at 95 °C for 0.5 h. The catalyst is still highly active after 6 cycles of recycling with 92.8% of FC and 100% of FMS in IP at 170 °C for 1.5 h and 90.1% of LA conversion and 100% of γ-valerolactone selectivity in water at 80 °C for 0.5 h.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2018
·Vol. 51
·期 03
·739-746
·
IF 2.722
Qing-Wen Song,Qing-Ning Zhao,Jing-Yuan Li,Kan Zhang,Ping Liu
It is promising and challenging to achieve the effective construction of carbonates using CO2 and a non-noble metal catalyst. Herein, selective catalytic conversion of CO2 and switchable alcohol candidates to produce linear or cyclic carbonates and α-hydroxy ketones via effective zinc catalyst was developed. A series of primary alcohols and cyclohexanol, 1,2-diols, and water can serve as nucleophiles to give alkyl or aryl 2-substituted-3-oxobutan-2-yl carbonates, substituted 1,3-dioxolan-2-ones, 3-substituted 3-hydroxybutan-2-ones, respectively with excellent selectivity and high yields.
研究领域:
化学
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催化科学
·
绿色化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2015
·Vol. 18
·期 1
·226-231
·
IF 8.02
Ran Ma,Liang-Nian He,Yue-Biao Zhou
An efficient and recyclable catalytic system of a Zn(O)4-coordinated complex e.g. 2-hydroxypyridine N-oxide zinc(II), Zn(OPO)2 and tetrabutylammonium iodide (TBAI) was developed for the cyclic carbonate synthesis from epoxides and CO2 without the use of any organic solvents. This easily prepared, low-toxic Zn(OPO)2 may have a strong Lewis acidity for the activation of epoxides and exhibited high activity (TOF up to 22 000 h−1) even at a CO2 pressure as low as 1 bar with a broad substrate scope. Furthermore, the catalyst can be easily recovered and reused five times without a significant loss of its catalytic activity.
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2015
·
IF 3.005
Limiao Lin,Yonghang Xu,Shuanjin Wang,Min Xiao,Yuezhong Meng
An economic and biocompatible Schiff base tri-zinc catalyst was used to synthesize homo/copolymers of l -lactide (LA) and ε-caprolactone (CL) in bulk at first time. Both 1 H and 13 C NMR analyses show that LA is more active than CL, resulting in a poly(LA- grad -CL) copolymer with gradient sequence structure. A series of copolymers containing varying LA/CL ratios were readily synthesized. The chemical structure of poly(LA- grad -CL) was fully investigated using NMR and GPC technologies. TGA, DSC, DMA and nanoindentation instruments were employed to evaluate thermal and mechanical properties of these polymers. The results indicate that polymer composition and chain structure have a great impact on the crystallization behavior and crystallinity, as well as the thermal and mechanical properties of the copolymers. Therefore, the performance of the copolymer can be then tailored by simply adjusting the ratios of LA to CL.
研究领域:
材料科学
·
高分子化学
·
生物医学工程
✓ 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）