APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Qunfeng Zhang,Wei Xu,Xiaonian Li,Dahao Jiang,Yizhi Xiang,Jianguo Wang,Jie Cen,Stephen Romano,Jun Ni
The preparation of supported palladium sulfides catalysts has attracted much attention due to their good sulfur-resistant properties in the hydrogenation of sulfur-containing compounds. In this work, we unambiguously demonstrated that Pd/C catalyst could be in situ sulfided by organic sulfur-containing reactant molecules and the sulfidation was highly dependent on temperature. The in situ sulfidation of Pd/C catalyst was composed of a reaction of Pd with the sulfur derived from the cleavage of C S bond of sulfur-containing reactant molecules, followed by a transformation to Pd x S y at high temperatures (around 120 °C). The sulfided Pd/C catalyst could be used for at least 18 recycles without a significant loss in its activity during the hydrogenation of sulfur-containing nitrobenzene at 180 °C with 3 MPa H 2 , which could be attributed to the stable presence of Pd 4 S and Pd 16 S 7 .
研究领域:
催化化学
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材料科学
✓ 已验证
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
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
ACS Applied Polymer Materials
·
2020
·
IF 0
Hui Dong,Yingying Wang,Hao Fu,Minheng Ye,Guangping Tang,Jinlong Pan,Xianping Xia
The hydrogen getter consisting of 1,4-bis[phenylethynyl]benzene (DEB) and a carbon-supported palladium catalyst (Pd/C) is limited by its powder forms in practical application. Development of the molded DEB-Pd/C is thus highly demanded. To solve the contradiction between molding and hydrogen-getter rate, herein, we prepared a porous polymer matrix composite for DEB-Pd/C by a facile one-phase removal method of their cocontinuous polymer matrices. Such a porous composite exhibits excellent hydrogen-getter activities. More interestingly, under low hydrogen partial pressure, the porous composite had a faster getter rate than that of powder getters. The significantly enhanced activity is attributed to the confinement effects of the continuous pore structure of the polymer frameworks, which further indicates its promise as a highly active and flexible supporting framework for hydrogen absorption or other gas–solid reactions.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
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
Nanoscale
·
2025
·
IF 5.1
Shaonan Tian,Zhenya Hu,Mengyuan Ma,Hui Liu,Jun Yang
Developing high-performance electrocatalysts is essential for the commercialization of fuel cells, but the commercial catalyst is still far from satisfactory in terms of catalytic activity and stability. Herein, we report a convenient solid-phase synthesis strategy that couples ball milling and rapid Joule-heating to prepare fine palladium nanoparticles supported on carbon substrate (Pd/C). The as-synthesized Pd/C catalyst shows excellent catalytic performance for typical electrochemical reactions, e.g., oxygen reduction reaction (ORR), ethanol oxidation reaction (EOR) and formic acid oxidation reaction (FAOR), compared to commercial Pd/C catalyst. We emphasize the multi-dimensional comparison of the obtained Pd/C product and commercial catalysts to illustrate the potential advantages of the synthesis method in industrial applications.
研究领域:
材料科学
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电化学
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能量转换
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纳米技术
✓ 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
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Xinjun He,Mengqiao Gao,Fukun Li,Zhiyang Tang,Jie Qu,Jinxing Long,Qiang Zeng,Xuehui Li
Catalytic hydrogenolysis of lignin has attracted steady attentions in regard of producing high-value aromatic chemicals from the renewable resource and achieving the “carbon neutrality” goal. However, current techniques for lignin hydrogenolysis are highly challengeable due to the necessity of pure H2 and relatively low yields in monomers. In this work, a novel and efficient approach has been proposed for the conversion of lignin to monophenols under readily available and cost-effective syngas. The results demonstrated that CO has the dramatic promotion on the bagasse lignin hydrogenolysis over commercialized Pd/C at 230 °C for 4 h, the yield of monophenols reaches 357.2 mg/g at 3.0 MPa syngas (CO/H2=2/1), which is approximately 1.7 times of that under pure H2. As evidenced by quantitative 31P NMR analysis, the promoting effects of CO on lignin depolymerization are positively correlated with the content of side-chain hydroxyl groups in lignin. Further investigations on lignin model conversion reveal that CO suppresses the dehydroxylation at Cα-OH, with concomitant enhancement of Cβ-O bond cleavage (increasing from 10% in H₂ to 64% in syngas). This inhibitory effect on side-chain hydroxyls elimination directly correlates with the 1.7-fold increase of monophenol yields observed during catalytic depolymerization. Therefore, this work provides a new insight in lignin depolymerization using industrial catalyst of Pd/C and the cost-effective syngas.
研究领域:
化学工程
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可再生能源
·
催化
·
生物质转化
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Riyang Shu,Qi Zhang,Longlong Ma,Ying Xu,Pengru Chen,Chenguang Wang,Tiejun Wang
The aim of this study is to explore the reaction mediums and conditions for producing high yield of valuable monomers from concentrated sulfuric acid hydrolyzed lignin. The solvent, temperature and time effects on the hydrogenolysis of hydrolyzed lignin were investigated under the catalysis of Pd/C and CrCl 3 . Supercritical methanol exhibits the best depolymerization performance, because of its unique diffusion, dissolution and acid-base properties. Afterwards, the influence of reaction temperature and time on depolymerization, repolymerization and coking during hydrogenolysis was examined in methanol. The high temperature is found to favor the depolymerization, with the β-O-4 linkages cleaved significantly. However, the repolymerization is promoted simultaneously, and a high amount of β-β groups form. These reactions are in constant competition with each other and the repolymerization is preferred at excessive high temperature, producing bulk char residues, that is coking. This study will provide a beneficial reference for the maximization of lignin waste valorization.
研究领域:
化学工程
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生物质转化
·
可再生资源利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Guozong Yue,Zhanxiong Li,Yakun Guo,Deshun Huang,Maobing Shuai,Qingsong Huang
The incorporation of DEB-Pd/C into polymers provides a possible solution to obtain various composite materials with customized properties. In this work, we selected SEBS as a substrate to prepare an ultra-thin flexible DEB-Pd/C@SEBS composite film . The mechanical properties and hydrogen uptake properties of composite films with different DEB-Pd/C contents and different thicknesses were investigated. The results show that these films possess excellent H 2 uptake and mechanical properties. We speculate that the microphase separation structure of these films results in high gas permeability and diffusion rate, which make the material have good compatibility. In addition, these films can be cut and bent into any shape, which can be applied to hetero-slit space easily and conveniently.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2014
·Vol. 17
·期 3
·1610-1617
·
IF 6.852
Bing Liu,Yongshen Ren,Zehui Zhang
In this study, Pd nanoparticles were immobilized on the core–shell structure C@Fe3O4 (carbon is the shell and Fe3O4 is the core) magnetic microspheres via in situ adsorption and reduction to generate the magnetically separable Pd/C@Fe3O4 catalyst. In this method, no excess reductant and capping reagents were required, and it is a clean, simple and green process for the preparation of the magnetic Pd nanocatalyst. The Pd/C@Fe3O4 catalyst showed high activity and extraordinary stability during the oxidation of biomass derived 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) under mild conditions. A study aimed at optimizing the reaction conditions such as reaction temperature, reaction solvent and base amount has been performed. Under optimal reaction conditions, HMF conversion of 98.4% and FDCA yield of 86.7% were achieved after 6 h at 80 °C. After reaction, the Pd/C@Fe3O4 catalyst could be easily recovered by an external magnet and reused without the loss of its activity.
研究领域:
化学工程
·
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2025
·
IF 3.1
Hongbo Yu,Weixing Ming,Wei Wei,Yanan Zhao,Xin Dong,Xianguo Wu,Gaowu Qin,Dongmao Yan
Amines represent crucial intermediates in fine chemical synthesis, finding extensive applications across pesticide, dye, and pharmaceutical industries. N,N-Dimethyl tertiary amines can be efficiently synthesized through reductive amination of dimethylamine. We developed an environmentally benign continuous flow reductive amination system employing a micro-packed bed reactor (μ-PBR) with a Pd/C catalyst prepared via direct impregnation. This system successfully produces N,N-dimethylcyclohexylamine (DMCHA) in an aqueous system, achieving high selectivity (99.5%), impressive space–time yields (2.7 × 104 g L−1 h−1), and operates without requiring additional additives. In addition, the reaction system demonstrated excellent stability during a 120-hour continuous test and proved suitable for both aromatic aldehydes and aromatic amines.
✓ 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）