Catalysts
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2017
·Vol. 7
·期 10
·311
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IF 3.082
Xing Li,Haiyang Zhang,Baochang Man,Lijuan Hou,Chuanming Zhang,Hui Dai,Mingyuan Zhu,Bin Dai,Yanzhao Dong,Jinli Zhang
The Ru-based catalysts, including Ru/AC (activated carbon), TPAP (tetrapropylammonium perruthenate)/AC, TPAP/AC-HNO3, and TPAP/AC-HCl, were prepared and assessed for the direct synthesis of vinyl chloride monomer. The results indicate that the TPAP/AC-HCl catalyst exhibits the best performance with the conversion falling from 97% to 91% in 48 hours’ reaction under the conditions of 180 °C, a GHSV(C2H2) of 180 h−1, and the feed ratioVHCl/VC2H2of 1.15. The substitution of RuCl3precursor with high valent TPAP species leads to more ruthenium oxides active species in the catalysts; the acidification treatment of carrier in TPAP/AC catalyst can produce an enhanced interaction between the active species and the modified functional groups on the carrier, and it is beneficial to inhibit the carbon deposition and sintering of ruthenium species in the reaction process, greatly increase the adsorption ability of reactants, and further increase the amount of dominating active species in the catalysts, thus improving the catalytic performance. This also provides a promising strategy to explore high efficient and economic mercury-free catalysts for the hydrochlorination of acetylene.Keywords:tetrapropylammonium perruthenate;acetylene hydrochlorination;Ru catalysts
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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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
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IF 3.171
Lutai Song,Li Liu,Mingyuan Zhu,Bin Dai
The continuous expansion of vinyl chloride production increases environmental pollution caused by mercury catalysts, which is an issue that urgently needs to be solved. Green and stable catalysts should be researched to alleviate this issue. In this research, Thiolactic acid acts as a ligand where sulfhydryl groups form a stable complex with Au on the surface of a spherical activated carbon (SAC). An Au-thiolactic acid/SAC catalyst was designed with a Au theoretical loading of 0.5% (mass) to overcome the disadvantages of traditional Au-based catalysts, such as a low conversion rate and poor life cycle. The ratio of Au to ligand was screened, and the activity was best when Au/S = 1:8. The formation of the Au-S bond was proven by FT-IR and UV–vis. The longevity test of the Au1S8 /SAC catalyst was carried out at 1200 h −1 for 50 h. Samples with reaction times of 0 h, 5 h, 10 h, 20 h, and 50 h were taken to monitor the catalyst status. The XPS and TPR tests proved that the Au-S bond broke as the acetylene hydrochlorination reaction proceeded. The DFT calculation proved that the Au-S bond is the active site, and the sulfur atom promotes the adsorption of C 2 H 2 by the catalyst.
研究领域:
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
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2020
·Vol. 22
·期 5
·2849-2857
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IF 3.43
Chaoyue Zhao,Xianliang Qiao,Zenghuimin Yi,Qingxin Guan,Wei Li
A green catalyst for acetylene hydrochlorination yielding a VCM is presented using imidazole as a single component metal-free catalyst. The mechanisms and reactivities of imidazole-catalyzed acetylene hydrochlorination have been investigated by combined computational and experimental studies. The electronic effects of ortho-substituents on the reactivities have also been investigated. Through theoretical calculations and experimental studies, the nitrogen-atom including a lone pair active site of single component imidazole for metal-free acetylene hydrochlorination is proposed. It is suggested that the nitrogen-atom including a lone pair of imidazole adsorbs an HCl molecule to form an imidazole-HCl complex, which serves as the active catalyst to participate in the reaction process of acetylene hydrochlorination. Besides, the results show that C2H2 assists in the electrophilic addition of HCl, undergoing an almost planar six-membered ring transition state. Computational studies on the ortho-substitution of the active sites will have an important impact on the catalytic efficiency.
研究领域:
化学
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催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
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2017
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IF 3.386
Danfeng Zhang,Shen Yao,Shuai Li,Jun Wang,Youwei Yao
A new thermal stabilizer , La-Gly (Gly = n -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-glycin), was synthesized. Through discoloration and dehydrochlorination tests at 180 °C, La-Gly is found to possess high stabilizing efficiency for poly(vinyl chloride) (PVC): as the mass ratio of La-Gly to PVC resin is increased from 0.3/50.0 to 2.0/50.0, the time to degradation of PVC samples increases from 90 min to 190 min. Studies on combinations of La-Gly and ZnSt 2 , and of La-Gly and dibenzoyl methane (DBM) show that the initial color of PVC is improved, as the ratio of ZnSt 2 to La-Gly or DBM to La-Gly is increased from 0.3/1.2 to 1.2/0.3. One sample (50.0 g PVC, 0.6 g ZnSt 2 , 0.9 g La-Gly, 3.4 g tributyl citrate) shows the best balance between initial color and long-term thermal stability (140 min). Studies on dynamic thermal stability of the samples (50.0 g PVC, x g La-Gly, 3.4 g tributyl citrate, x = 0.3, 0.6, 0.9, 1.2, 1.5, 2.0) show that when x equals 1.2, the thermal dynamic stability time is 24.5 min, much longer than 6.4 min and 4.8 min, respectively, for two controls (50.0 g PVC, 1.5 g LaSt 3 , 3.4 g tributyl citrate; 50.0 g PVC, 0.6 g CaSt 2 , 0.9 g ZnSt 2 , 3.4 g tributyl citrate).
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
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2024
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IF 3.8
Zifei Yan,Grace Dai Zhen Lee,Jian Deng,Guangsheng Luo
The synthesis of terminal epoxides, which are vital components in pharmaceuticals and resins, often involves dehydrochlorination of β-chlorohydrins. Although intrinsic kinetics indicate that the dehydrochlorination reaction in the presence of sodium hydroxide could be very rapid, the practical implementation could always be hindered by long reaction time and low conversion rate. Extended contact between the product and the alkaline solution can lead to hydrolysis of the epoxy group, thus necessitating the process intensification to realize higher production efficiency and selectivity. Here, by characterizing thermodynamic equilibrium data and in-situ recording of the reaction that proceeded in a constant interphase reactor, the heterogeneous dehydrochlorination is demonstrated to occur primarily in the organic phase, and the overall reaction rate depends on the equilibrium concentration of sodium alkoxides. This finding, which is fundamentally different from the traditional view that chlorohydrin is first dissolved in the aqueous phase and then reacts with NaOH, leads us to use inert alcohols to assist in the extraction of NaOH. Based on this method, the reaction time can be reduced over 80 % both in batch and continuous reactors. Besides, the method is demonstrated to be effective in the dehydrochlorination of five different long-chain β-chlorohydrins.
研究领域:
化学工程
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有机合成
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2020
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IF 4.794
Yusheng Lu,Fangjie Lu,Mingyuan Zhu
In industry, mercury catalysts are mainly used in hydrochlorination of acetylene. However, the sublimation of mercury considerably harms human health and the environment. Therefore, the development of green catalysts is particularly demanding to eliminate the negative effects of such toxic catalysts. Based on this, we used a green, low-cost carrageenan as raw material. A nitrogen-modified carbon material was prepared by nitrogen modification using urea. Based on the reaction conditions of the catalyst dosage = 0.75 g, WHSV = 2.22 mL/g/min, temperature = 260 °C, the conversion of the nitrogen-modified catalyst was 98.7%. Various characterization methods had demonstrated that the nitrogen modification produced a large amount of nitrogen and that the nitrogen element was sufficiently dispersed in the carbon material. In addition, identification of the appropriate annealing temperature greatly improved the adsorption catalytic capacity for acetylene. Therefore, an environmentally friendly non-metallic catalyst was developed, which also providing essential feedback for future industrial development.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2021
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IF 3.498
Kai Su,Jiachengjun Luo,Yongjun Ji,Xingyu Jiang,Jing Li,Jianling Zhang,Ziyi Zhong,Fabing Su
Here we report the first synthesis of nearly pure-phase Cu 3 Si alloy that can be a highly efficient catalyst in the hydrochlorination of silicon reaction. This material was prepared by a high-temperature (1050 °C) calcination method in which copper and silicon powders were used as the reactants. The X-ray photoelectron spectroscopy (XPS) study revealed that the Cu and Si atoms in the Cu 3 Si alloy carried part of positive and negative charge, respectively. When employed as the catalyst in the silicon hydrochlorination to SiHCl 3 (TCS) for the production of Si polycrystals for Solar cell, the sample Cu 3 Si exhibited excellent low-temperature catalytic performance: the Si conversion and TCS selectivity respectively achieved 41.1% and 96.1% at 250 °C. Notably, its TCS yield at 250 °C was 1.2 times higher than that of the industrial catalyst-free system at 350 °C. Detailed analysis of the reaction process showed that the positively charged Cu atoms and negatively charged Si atoms in Cu 3 Si alloy could cleave the H–Cl bond in the reactant HCl and make the combination of H and Cl atom with Si atoms easier. Meanwhile, the reaction between the remaining Cu atom and Si was accelerated, leading to the generation of more active Cu 6.69 Si and ultimately superior catalytic performance. This work deepens the fundamental understanding of the hydrochlorination of silicon reaction, and provides an avenue for the synthesis of Si-based alloy catalysts .
研究领域:
材料科学
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化学工程
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可再生能源
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2018
·Vol. 10
·期 18
·4090-4099
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IF 4.674
Hang Li,Botao Wu,Fumin Wang,Xubin Zhang
Graphical No DMPUing ground : Efforts are made to design mercury-free catalysts from both technical and economic aspects. Here, a Ru-based catalyst with a low Ru content is prepared by adding DMPU as an efficient stabilizer. The catalyst shows high activity and stability. A new Ru-based catalyst system based on N,N′-Dimethylpropyleneurea (DMPU) was developed for the acetylene hydrochlorination reaction in this study. The optimal 1 % Ru-10 %DMPU/AC catalyst exhibits the best activity with the acetylene conversion of 87.6 % under 170 °C and the GHSV (C 2 H 2 ) of 900 h −1 . Additionally, the Ru-10 %DMPU/AC with lower Ru content (0.2 wt%) displayed excellent activity and stability with acetylene conversion of 81.3 % after 200 h under the conditions of 170 °C and C 2 H 2 GHSV of 180 h −1 . The characterization results indicate that the presence of DMPU could improve the dispersion of the catalytic species and provide full protection to prevent the sintering of the ruthenium particles and to inhibit the reduction of active ruthenium oxide component. Moreover, the catalytic property, characterizations and theoretical calculation results reveal that the ability to adsorb and activate HCl reactant with the addition of DMPU via its strong hydrogen bonding plays a significant role on the high stability of the Ru-DMPU/AC catalyst system.
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
CATALYSIS TODAY
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2024
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IF 5.2
Heng Wang,Yubin Tian,Ming Xu,Xu Cheng,Jiawei Huang,Hongda Li,Yan Li,Yuying Shi,Lanxin Ye,Hongxia Liu,Qixun Shi,Chuan Wang
To achieve the sustainable production of acetylene hydrochlorination , the development of green and efficient mercury-free catalysts is a challenge. Ru-based catalysts are potential alternatives, but they are not applicable due to their high price and poor stability. Herein, we synthesized a series of low loading Ru-based catalysts modified by nitrogen-containing ionic liquids . These catalysts show high activity and stability based on the interaction between nitrogen-containing ionic liquids and Ru species. Among them, 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride modified Ru-based catalyst, 0.3%Ru-N4/AC, exhibits excellent catalytic activity at 180 °C and a GHSV (C 2 H 2 ) of 170 h −1 , with an acetylene conversion of 94.3%. The addition of ionic liquids effectively promotes the dispersion of Ru species and increases the relative content of active Ru species on the activated carbon support. Simultaneously, the addition of ionic liquids also inhibits the reduction of active Ru species and prevents coke deposition, therefore improving the catalyst stability. 0.3%Ru-N4/AC catalyst also exhibits excellent stability over 150 h, demonstrating its potential as a mercury-free catalyst for acetylene hydrochlorination.
研究领域:
化学工程
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催化材料
✓ 已验证
DOI
高影响因子
ACS Catalysis
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2025
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IF 13.1
Xinping Duan,Yuxin Zhao,Hung-Lung Chou,Jiachang Zuo,Ruixin Wang,Weizhou Jiao,Huihuang Fang,Yanping Zheng,Haiqiang Lin,Linmin Ye,Youzhu Yuan
Metals atomically anchored on oxides have actively realized ultimate atom efficiency. However, a “molecular cork” effect causes the intrinsically reactive sites to remain dormant in various important catalytic processes. Here, we report a strategy to waken dormant atomic Au on cobalt-doped CeO2 islands (Au/CoCeO2) that are typically recognized as barely active in acetylene hydrochlorination by precisely controlling reversible C2H2 spillover facilitated by porous carbon materials, igniting its reactivity of Au-oxo sites and enhanced stability. In this vein, the C2H2 coverage on the nitrogen-doped carbon (NC) surface reversibly spills over onto HCl-corked metal sites, uncorking the strongly bound HCl. The Au/CoCeO2 + NC system displays a 2 orders of magnitude higher activity than modular Au/CoCeO2 and obtains an enhanced catalytic activity and durability than the state-of-the-art catalyst, Au/NC. This contribution unveils a distinct Eley–Rideal-like mechanism that exists on the Au/CoCeO2 + NC system, exchanging the conventional Langmuir–Hinshelwood pathway dominated over Au/NC. Collectively, our findings reinforce the importance of taming the reaction pathways for advancing catalyst design.
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
APPLIED CATALYSIS A-GENERAL
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2020
·
IF 5.006
Yubing Hu,Yan Wang,Yulian Wang,Wei Li,Jinli Zhang,You Han
In order to develop a cut-price, high-efficiency non-mercuric catalyst for acetylene hydrochlorination reaction, several kinds of supported Cu-based catalysts containing phosphoramide ligands have been synthesized by wet impregnation method. The outstanding catalytic activity was obtained over 15 %Cu10 %HMPA/SAC catalyst with acetylene conversion of 87.25 % in the test conditions of T =180 °C, GHSV (C 2 H 2 ) =180 h −1 and V (HCl): V (C 2 H 2 ) = 1.2. The catalyst with optimal HMPA ligand also exhibited splendid stability in 100 h lifetime test. The analysis for XRD, TEM, TGA, ICP, H 2 -TPR and XPS indicated that HMPA ligand can improve Cu species dispersion, restrain coke deposition, suppress loss of loading Cu, and stabilize valence state of active Cu species. Due to electron transfer mechanism, steady coordination structure between Cu and HMPA led to favorable properties of Cu-based catalyst, which was further proved by FT-IR, Raman spectra, O 1s XPS spectra integrated with DFT calculations.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
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2018
·Vol. 64
·期 7
·2536-2544
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IF 3.326
Lifeng Yang,Qiwei Yang,Jingyi Hu,Zongbi Bao,Baogen Su,Zhiguo Zhang,Qilong Ren,Huabin Xing
Ionic liquid (IL)-stabilized metal nanoparticles (NPs) have attracted increased attention as novel catalysts for various reactions due to their excellent stability and high activity. However, the high viscosity of ILs limits their applications. Here, for the first time, we reported an NPs@IL-cosolvent liquid–liquid biphasic system for metal NPs catalysis. The NPs were successfully confined to IL phase, and abundant IL droplets containing NPs were generated under the reactant flow. The NPs@IL droplets served as microreactors for the catalysis; while the low viscosity organic phase enabled the rapid mass transfer of substances. The biphasic system exhibited improved performance for acetylene hydrochlorination than that of the pure IL system. An acetylene conversion of 98% and a selectivity of 99.5% were achieved along with a 90% decrease on IL usage. The tolerable gas hourly space velocity in the biphasic system for a satisfactory conversion was almost double that of the pure IL system. © 2018 American Institute of Chemical Engineers AIChE J , 64: 2536–2544, 2018
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）