BIORESOURCE TECHNOLOGY
·
2014
·
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
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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
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
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可再生能源
✓ 已验证
DOI
高影响因子
Journal of Chemistry
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2018
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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
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 4
·e53363
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IF 3.057
Mali Xie,Kexin Peng,Yangyang Luo,Qi Zhang,Linjun Shao,Shaofeng Zhong,Shujing Zhou,Jinjing Li,Chenze Qi
Pd/C embedded polystyrene fibers were successfully prepared by electrospinning. The polystyrene molecules were then cross-linked by paraformaldehyde in sulfuric acid to improve the solvent resistance of composite fibers. SEM images conformed the preparation of uniform and smooth composite fibers. FT-IR spectra demonstrated that the polystyrene molecules inside fibers have been sulphonated and crosslinked. Heck reactions were used to evaluate the catalytic performance of these novel composite fibers. The catalysis results show that this composite fiber mat catalyzed Heck reactions could be evidently promoted by using preferred reducing alcohol agent and solvent. Under the optimized reaction conditions, this composite fiber mat could effectively catalyze the Heck reactions of aromatic iodides with n-butyl acrylate to afford the products with satisfied yields. Especially, compared with the particulate Pd/C catalyst, the separation and recycling of this fibrous catalyst from the reaction mixture were significantly improved due to the larger fibrous structure. At last, this fiber catalyst was successfully reused for eight times with little loss of initial catalytic activity, which was even better than the pristine Pd/C catalyst. Hence, embedment of particulate supported metal catalysts inside the crosslinked polystyrene fibers can effectively improve their catalytic performance and handiness.
研究领域:
化学工程
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材料科学
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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
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
Catalysis Science & Technology
·
2020
·Vol. 10
·期 12
·4099-4108
·
IF 5.721
Ting Qu,Qiang Tan,Liting Liu,Shengwu Guo,Sai Li,Yongning Liu
The wide application of direct ethanol fuel cells (DEFCs) was blocked by the sluggish catalytic activity of catalysts, insufficient ionic conductivity of the polymer electrolyte membrane (PEM), and ethanol crossover issues. To overcome the problems mentioned above, a novel DEFC system with a polymer fiber membrane (PFM) and nonplatinum catalysts is proposed. In this system, the performance of the anode catalyst Pd/C is significantly promoted by homogeneous Ni-doped SnO2 nanoparticles, and the inexpensive permeable PFM is used as a substitute for the PEM. Due to the remarkable catalytic activity and the optimized resistance, the PFM-based DEFC exhibits encouraging performance, which can afford a peak power density of 47.4 mW cm−2 with a porous NiCo2O4 cathode catalyst. Moreover, it can operate continuously for 100 h with only 4.56% drop in electrical output. Therefore, this study provides a very effective strategy for optimizing DEFCs with low cost and high performance.
研究领域:
能源科学
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材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 11
·2475
·
IF 3.267
Yanliang Yang,Dexi Yang,Chi Zhang,Min Zheng,Ying Duan
The development of a simple and durable catalytic system for the production of chemicals from a high concentration of a substrate is important for biomass conversion. In this manuscript, 5-hydroxymethylfurfural (HMF) was converted to 1-hydroxy-2,5-hexanedione (HHD) using the combination of commercial Pd/C and acetic acid (AcOH) in water. The influence of temperature, H2pressure, reaction time, catalyst amount and the concentration of AcOH and HMF on this transformation was investigated. A 68% yield of HHD was able to be obtained from HMF at a 13.6 wt% aqueous solution with a 98% conversion of HMF. The resinification of intermediates on the catalyst was characterized to be the main reason for the deactivation of Pd/C. The reusability of the used Pd/C was studied to find that most of the activity could be recovered by being washed in hot tetrahydrofuran.Keywords:HMF;1-hydroxy-2,5-hexanedione;acetic acid;Pd/C;high concentration
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
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Yongwan Gu,Yunyan Li,Jiaoxia Zhang,Huiying Zhang,Chunhua Wu,Jing Lin,Juying Zhou,Yuhang Fan,Vignesh Murugadoss,Zhanhu Guo
Pd/C catalysts were prepared by an incipient-wetness impregnation and their catalytic performance in disproportionation of rosin was investigated. The texture structure, groups on the activated carbon surfaces, and acidity were characterized by N 2 physisorption-desorption, Fourier transform infrared spectroscopy (FTIR), and temperature-programmed desorption (TPD). The Pd/AC3 (treated at 443 K) had the highest Pd dispersion (23.60%) with the highest specific surface area of activated carbon (1057 m 2 /g). Nevertheless, the Pd/AC0 (original carbon black) had the lowest Pd dispersion (13.07%) with a lower specific surface area of original activated carbon (994 m 2 /g). Pd/AC3 presented a considerable catalytic activity in the rosin disproportionation reaction, with 64.15% dehydroabietic acid and without abietic acid in product. However, Pd/AC0 (Pd supported on the original carbon) showed a much lower catalytic activity in the rosin disproportionation reaction, with 42.64% dehydroabietic acid and 3.59% abietic acid in product.
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
JOURNAL OF THE ENERGY INSTITUTE
·
2016
·
IF 1
Nan Li,Wei-Yan Xia,Chang-Wei Xu,Shuang Chen
This study investigated Pt/C and Pd/C catalysts promoted by Au for glycerol electrooxidation in alkaline medium . The results show that addition of Au can significantly promote the catalytic activity and stability of Pt/C and Pd/C for glycerol electrooxidation. The catalysts with a weight ratio of 4:1 for Pt to Au and Pd to Au show the best performance for glycerol electrooxidation and the PtAu(wt 4:1)/C shows a better performance than the PdAu(wt 4:1)/C. Glycerol electrooxidation on the PdAu(wt 4:1)/C has a better stability than that on the Pt/C. The results show that the PdAu(wt 4:1)/C can give a better discharge performance than the Pt/C in a direct glycerol fuel cell. Electrooxidation of pre-adsorbed CO has been used to explain the results.
研究领域:
化学
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催化科学
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能源材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
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
·
催化反应
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）