JOURNAL OF CATALYSIS
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2018
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IF 6.759
Juan Du,Jiaren Zhang,Yong Sun,Wenlong Jia,Zhihao Si,He Gao,Xing Tang,Xianhai Zeng,Tingzhou Lei,Shijie Liu,Lu Lin
Catalytic transfer hydrogenation (CTH) of bio-derived furfural (FF) to furfuryl alcohol (FFA) was performed using the physically mixed CuO-Pd/C as catalyst and formic acid (FA) as hydrogen donor. The evolution investigation of Cu showed the precursor CuO firstly dissolved into Cu 2+ by FA and then formed coordination polymer-copper(II), which uniformly dispersed in reaction solution of 1, 4-dioxane. Subsequently the Cu 2+ was in-situ reduced and Cu-Pd alloys formed simultaneously. The in-situ prepared nano Cu-Pd/C catalyst exhibited the best performance with a complete FF conversion and FFA selectivity of 98.1%. Reaction conditions test suggested that the FFA selectivity was greatly dependent on the Cu content. The underlying mechanism revealed that the Pd in Cu-Pd alloys mainly promoted the FF conversion by enhancing hydrogen adsorption, while the nano Cu for increasing FFA selectivity; the Cu-Pd alloys functioned in synergistic way. Leaching and recycling tests demonstrated an excellent stability of the Cu-Pd/C catalyst.
研究领域:
化学工程
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Guodian Zhu,Yuehua Wu,Yuebin Xi,Shaoqu Xie,Guoqiang Yin,Xiaojing Lv,Xuliang Lin
Lignin has immense potential for the production of monoaromatics that can be further prepared as target chemicals or alkyl biofuels. In this work, experiments and density functional theory (DFT) calculations were employed to investigate the effect of benzylic alcohol ( α -hydroxyl group, C α H─OH) dehydration to α , β -alkenyl group (C α = C β ) on the enhancement of the β -aryl ether ( β -O-4) bond cleavage reactivity of lignin model dimer over Pd/C by formic acid. This study demonstrated that the β -O-4 bond cleavage reactivity was significantly enhanced via the benzylic alcohol dehydration to C α = C β . The cleavage reactivity of the β -O-4 bond attached to C α functional groups was in the order of α -hydrogen atom (C α H─H) > C α H─OH > α -carbonyl group (C α = O). An easy formation of the C α H─H from the C α = C β hydrogenation led to the enhancement of the β -O-4 bond cleavage reactivity being achieved. The β -O-4 bond cleavage rate was increased by 6.2 times in the presence of the C α H─H compared to the C α = O. Due to few and lower required energy barriers after C α H─OH dehydration, the β -O-4 bond attached to the C α = C β was more thermodynamically favorable to be cleaved. The work highlights the prospect of efficient depolymerization of lignin into monoaromatics.
研究领域:
化学工程
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可再生资源
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2014
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IF 5.039
Riyang Shu,Jinxing Long,Zhengqiu Yuan,Qi Zhang,Tiejun Wang,Chenguang Wang,Longlong Ma
An efficient lignin depolymerization process with highly controllable product distribution was presented using metal chloride (MCl x ) cooperated with Pd/C. The catalytic performances of MCl x were investigated. The effect of reaction conditions on the lignin depolymerization and products distribution were also studied. Results showed that more than 35.4% yield of phenolic monomer including 7.8% phenols and 1.1% guaiacols could be obtained under optimized condition. And the product distribution can be efficiently controlled by the modification of the metal cation through different pathway of Lewis acid catalysis and coordination catalysis. Furthermore, the Pd/C catalyst showed an excellent recyclability, where no significant loss of the catalytic activity was exhibited after 3 runs. Moreover, the product control mechanism was proposed.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of CO2 Utilization
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2016
·
IF 4.764
Xiying Fu,Dagang Zhou,Kai Wang,Huanwang Jing
Pd/C was found to be an excellent catalyst in the coupling reaction of carbon dioxide and epoxides with tetrabutylammonium iodide (TBAI) as cocatalyst and the corresponding cyclic carbonates were obtained in good yields and high selectivities. 3-Chloropropylene carbonate was synthesized under extremely mild conditions of room temperature and atmosphere. The proposed mechanism was also calculated and confirmed by DFT. The palladium catalyst could be simply recycled and reused for 5 times without significant loss of activity.
研究领域:
化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Chemistry
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2018
·
IF 1.726
Zou Bin,Chen Xueshan,Xia Jiaojiao,Zhou Cunshan
Conversion of HMF into FDCA was carried out by a simple and green process based on alkaline ionic liquid (IL) modified Pd/C catalyst (Pd/C-OH−). Alkaline ionic liquids were chosen to optimize Pd/C catalyst for special hydrophilicity and hydrophobicity, redox stability, and unique dissolving abilities for polar compounds. The Pd/C-OH− catalyst was successfully prepared and characterized by SEM, XRD, TG, FT-IR, and CO2-TPD technologies. Loading of alkaline ionic liquid on the surface of Pd/C was 2.54 mmol·g−1. The catalyst showed excellent catalytic activity in the HMF oxidation after optimization of reaction temperature, reaction time, catalyst amount, and solvent. Supported alkaline ionic liquid (IL) could be a substitute and promotion for homogeneous base (NaOH). Under optimal reaction conditions, high HMF conversion of 100% and FDCA yield of 82.39% were achieved over Pd/C-OH− catalyst in water at 373 K for 24 h.
研究领域:
催化化学
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2021
·Vol. 96
·期 11
·3043-3051
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IF 3.174
Neng Xiong,Jin-Rong Huang,Sheng Wei,Ji-Wei Song,Zhong-Ce Hu,Ya-Ping Xue,Yu-Guo Zheng
BACKGROUND Miglitol is a potent alpha-glucosidase inhibitor that is used as a hypoglycemic agent. The industrial synthesis route of miglitol involves the biotransformation from N -2-hydroxyethyl glucamine to 6-( N -hydroxyethyl)-amino-6-deoxy-alpha- l -sorbofuranose and the subsequent hydrogenation from 6-( N -hydroxyethyl)-amino-6-deoxy-alpha -l- sorbofuranose to miglitol. This study comprehensively investigated the hydrogenation process and catalyst, and the effect of operating parameters on the product yield. RESULTS A 55.6% miglitol yield was obtained under the following optimal reaction conditions: 5 g L −1 palladium/carbon (Pd/C) (5% Pd); ethanol addition 1:1 ethanol:water (v/v); 80 g L −1 6-( N -hydroxyethyl)-amino-6-deoxy-alpha -l- sorbofuranose; reaction temperature 25 °C; solution pH 6; stirring speed 500 rpm; hydrogen pressure 1 MPa. The yield obtained was much higher than the average 36.8% in current industrial production. Catalyst deactivation during reuse was found to be caused by biological impurities, especially the macromolecular impurities introduced in previous biotransformation. The deposition of impurities on the porous support of the Pd/C catalyst may be the direct cause of catalyst deactivation. CONCLUSION Optimal conditions for the hydrogenation in the synthesis of miglitol were determined. It also was confirmed that biological impurities need to be completely removed to avoid catalyst deactivation and to improve catalyst reusability.
研究领域:
生物化学
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制药工程
✓ 已验证
产品关联
DOI
高影响因子
Green Processing and Synthesis
·
2017
·Vol. 6
·期 4
·363-370
·
IF 0.782
Zhihao Li,Zhihao Bi,Lifeng Yan
As the major composite of biomass, lignin can be utilized as feedstock for valuable chemicals, especially phenols. Catalysis hydrogenation of lignin is an attractive route for the conversion. However, most of them require hydrogen gas under high pressure which is dangerous. Hydrogen transfer reaction provides an alternative route to degrade and hydrogenate lignin or its units to small molecular compounds. Here, a two-step method has been employed using Raney Ni and Pd/C catalysts consecutively for hydrogen transfer catalysis for lignin. The results reveal that lignin can be degraded efficiently about 90% during conversion, and the major products are phenols with ~30% in yield. It provides a new green method for converting natural lignin to valuable chemicals.
研究领域:
生物质化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·
IF 1.7
Gao Xinglong,Qiu Feifei,Xie Hongzhao,Chen Xiaopeng,Wu Chenghong,Chen Yutong,Liang Jiezhen,Wang Linlin
In the present work, efficient catalytic hydrogenation of acrylic rosin (AR) were extensively investigated. Qualitative and quantitative analysis of AR and hydrogenated acrylic rosin (HAR) were carried out by GC and GC–MS, and the reaction pathway network about catalytic hydrogenation of AR was constructed. In addition, a Pd/C catalyst with well-dispersed ultrafine nano-palladium was prepared by impregnation method using Pd(NO 3 ) 2 ·2H 2 O precursor and put into use for the catalytic hydrogenation of AR. The structural properties of the catalyst were measured via XRD, TEM, ICP-OES, XPS, and BET. The characterizations showed that the ultrafine Pd nanoparticles (NPs) with an average Pd NPs size of 2.29 nm and consisting of 3.1% Pd were equably loaded on the surface of activated carbon. Benefiting from well-dispersed ultrafine Pd NPs, the catalyst exhibits outstanding activity in the hydrogenation of AR at 180 °C and 5 MPa, which shows 1.9 times superior activity than a commercial 10% Pd/C. The quality of prepared HAR is similar to the commercial HAR (Gardner color < 1, acid value of 235 mg KOH/g, softening point of 129 °C, 35% conversion rate of acrylpimaric acids). Graphical abstract
研究领域:
化学工程
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催化材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 106
·104398-104406
·
IF 3.289
Cong Zhang,Jingbo Qi,Jing Xing,Si-Fu Tang,Liang Song,Yuanyuan Sun,Chuanhui Zhang,Hongchuan Xin,Xuebing Li
Aqueous phase catalytic upgrading of lignin monomers to hydrocarbons via hydrodeoxygenation (HDO) has been explored using a combination of Pd/C and HZSM-5 catalysts under 2 MPa of H2 (ambient temperature). Model monomers with varying numbers of methoxy groups, including phenol, anisole, guaiacol and 2,6-dimethoxy-phenol, were chosen as lignin model compounds. Mechanistic studies revealed cascade and parallel reaction pathways via hydrogenation and dehydration (hydrolysis) processes, which were catalyzed by Pd/C and HZSM-5, respectively. Hydrogenation was preferred at lower temperature, whereas higher temperature was favorable for the removal of oxygen-containing functional groups. The effect of methoxy groups on the HDO of these monomers was also investigated systematically. Basically, the conversion of multi-substituted monomers was tougher than that of mono-substituted ones, due to steric constraint and the inhibition of the electron-donating hydroxyl group. The selectivities to cyclohexane from phenol and anisole were improved significantly by increasing the temperature to 413 K. However, cyclohexanone was preferably produced over cyclohexane when using model compounds with multi-substituents (guaiacol and 2,6-dimethoxy-phenol), even at temperatures above 513 K. Comparative experiments were also conducted on the HDO of 1,2-cyclohexanediol with or without the presence of phenol, which clearly suggested that the further HDO of guaiacol and 2,6-dimethoxy-phenol was inhibited, probably due to the strong interactions between cyclohexanediol molecules and Brønsted acid sites.
研究领域:
化学工程
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催化反应
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 8
·1921
·
IF 3.1
Yu Wang,Tao Xing,Lifeng Yan
Hydrogen is a dangerous gas as it reacts very easily with oxygen and may explode; therefore, the accumulation of hydrogen in confined spaces is a safety hazard. Composites consisting of unsaturated polymers and catalysts are a common getter, where the commonly used polymer is 1,4- diphenylethynyl benzene (DEB). Silicone rubber (SR) is a good carrier for hydrogen-absorbing materials due to its excellent chemical stability and gas permeability. In this work, polysiloxane, water, and a emulsifier are ultrasonically injected into a uniform emulsion, and the hydrogen getter DEB-Pd/C (Palladium on carbon) is then added. Under the catalysis of platinum (Pt), the cross-linking agent undergoes a hydrosilylation reaction to cross-link polysiloxane in emulsion to form silicone rubber. Then, the water was removed by freeze-drying, and the loss of water constructed a porous frame structure for silicone rubber, thus obtaining porous silicone rubber. The difference in hydrogen absorption performance between porous silicone rubber and ordinary silicone rubber was compared. It was found that, with the increase in water in the emulsion, the porous frame of silicone rubber was gradually improved, and the hydrogen absorption performance was improved by 243.4% at the highest, almost reaching the theoretical saturated hydrogen absorption capacity. Porous silicone rubber was prepared by emulsion mixing, which provided a new idea for further improving the hydrogen absorption performance of silicone rubber.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Mengdi Li,Anyan He,Liheng Deng,Qingmao Yang,Haodong Chu,Chun Shen,Tianwei Tan
Catalytic conversion of cellulose in biomass into 2,5-hexanedione is a significant step for the production of biobased p-xylene (PX), and a precise understanding about the effect of the coexisting hemicellulose and lignin components is extremely essential and desirable, but still severely deficient. Herein, we investigate the above issue by catalytic tests, structural characterizations, and composition analysis. Catalytic tests confirm that the coexisting hemicellulose does not affect cellulose conversion and could be converted into 5-chloro-2-pentanone, while the lignin component plays a detrimental role. Lignin and the oligomers from lignin hydrogenolysis can block the catalytic active sites via deposition due to the strong interaction between lignin and Pd/C catalyst. Meanwhile, there is noncovalent interaction between lignin and cellulose, reducing the accessibility of cellulose to the catalytic active sites including the Pd/C and acidic sites. Basic treatment by NaOH aqueous solution could result in simultaneous removal of lignin and fracture of the biomass structure and hence higher accessibility for the Pd/C catalyst. When the biomass is treated by NaOH with the concentration of 1.0 wt %, the amount of lignin (8.3 wt %) is low enough and the structure is fractured enough to achieve the yield of HDO and DMF comparable to that using sole cellulose as the reactant.
研究领域:
生物质化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Energy Science & Engineering
·
2019
·Vol. 7
·期 3
·881-889
·
IF 2.893
Yanjie Zhu,Yang Yang,Xiaoguang Wang,Heng Zhong,Fangming Jin
Conversion of CO 2 into useful chemicals has been regarded as one promising method to mitigate the problem of global warming. However, developing an efficient method for CO 2 reduction with facile hydrogen source is still a great challenge. In this study, a new and straightforward method to convert NaHCO 3 , a model compound of CO 2 in basic solution, into formate with 2-pyrrolidone, a model compound of protein-containing biomass, as the reductant on a Pd/C catalyst in water was proposed. Results showed that a formate yield up to 30% from bicarbonate was successfully obtained over the Pd/C catalyst, and the Pd/C catalyst exhibited good catalytic activity and stability. Detailed studies revealed that the propanol generated from the decomposition of 2-pyrrolidone under hydrothermal conditions acted as the actual reductant and hydrogen source for the bicarbonate reduction to formate. Since 2-pyrrolidone can be readily generated from the proteins contained in biomass, the present research provides a promising technology of NaHCO 3 reduction with biomass as the hydrogen source and the renewable energy input, thus it is green, sustainable, and promising for practical application.
研究领域:
化学
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环境科学
·
可再生能源
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）