BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Guodian Zhu,Xueqing Qiu,Ying Zhao,Yong Qian,Yuxia Pang,Xinping Ouyang
A new two-step lignin depolymerization strategy was developed, in which the benzylic alcohols in lignin was methylated under microwave irradiation, followed by a hydrogenolysis for the cleavage of β O 4 bond with Pd/C as the catalyst. The results showed that an efficient and selective catalytic methylation of benzylic alcohols was achieved with various lignin model compounds, and the acidic environment promoted the methylation of benzylic alcohol. Methylation of benzylic alcohol increased the β O 4 bond cleavage rate by 55.9%, and improved products selectivity . Preliminary study of lignin depolymerization illustrated that methylation pretreatment of benzylic alcohols facilitated lignin depolymerization to produce aromatic monomers and reduced the oxygen content of aromatic monomers.
研究领域:
生物化学
·
可再生资源与环境科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Hui Chen,Jie He,Jinsheng Sun
The production of cyclohexanone, of industrial importance, is at a distance to environment friendly and efficiency. As a solution, a mild sustainable catalytic hydrogenation is presented herein, of phenol into cyclohexanone on Pd/C with potassium formate the hydrogen donor under open atmosphere. Some important reaction conditions, such as temperature, reaction time, catalyst, amount of potassium formate, etc. were investigated and analyzed. The positive growth was found to accelerate the conversion rate of phenol while reducing cyclohexanone selectivity by weakening the protection of phosphotungstic acid. Phosphotungstic acid was confirmed to be the co-catalyst exhibiting the highest activity under given conditions. Based on experiments, we have made reasonable assumptions about the reaction mechanism, while the reaction kinetics proves high reaction rates within a wide temperature range, indicating the reaction to be quick process. Furthermore, the good reusability and recyclability of Pd/C catalyst is verified to benefit future industrial applications.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
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
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of CO2 Utilization
·
2018
·
IF 5.503
Yu-Nong Li,Xiao-Fang Liu,Liang-Nian He
The oxazolidinone as one kind of annular CO 2 derivatives has been hydrogenated by a new catalytic system Pd/C-TMGPEG 150 Me (polyethylene glycol-functionalized 1,1,3,3-tetramethyl guanidine), affording two valuable products i.e. formic acid and the corresponding secondary alkyl-(2-arylethyl)amines in the high yields of 89% and 98%, respectively. This hydrogenation can be carried out smoothly under relatively mild conditions of 60 °C, 4 MPa of H 2 with a liquid/solid carbon source (oxazolidinone) instead of high pressure CO 2 . The notable results can be successfully obtained even at room temperature under atmospheric H 2 pressure. This one stone two bird strategy is applicable to series of 5-aryl-2-oxazolidinones and opens up a novel way of synthesizing linear secondary alkyl-(2-arylethyl)amines without the selectivity issues, and validates a potential alternative approach for indirect conversion of CO 2 to energy-related products formic acid, as oxazolidinones can be readily obtained from hydrogenation of CO 2 .
研究领域:
化学
·
催化科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 7
·2019-2029
·
IF 2.911
Liu Anqiu,Huang Zhong,Wang Xiaochen
Abstract A new method has been developed for the oxidation of glucose into gluconic acid over Pd/C catalysts under the room temperature and atmospheric pressure. The carbon support was prepared by the hydrothermal treatment of renewable glucose, thus contained abundant active oxygen species. The Pd/C catalyst showed high catalytic activity towards the oxidation of glucose into gluconic acid. A 100% glucose conversion and a 98% gluconic acid yield were attained within 2 h at 0.1 MPa and room temperature. Structural analysis showed that the Pd paricle sizes of the catalysts were in the range of 10.1–16.2 nm influenced by the loading of Pd. The structure/size study showed that the catalyst with optimal particle size of 10.9 nm exhibited the highest TOF (0.2388 mol glucose mol Pd /s). The catalyst showed no significant loss of activity after recycled for four times. Graphical Abstract
研究领域:
化学催化
·
绿色化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Jiasheng Zhou,Zimo Lou,Kunlun Yang,Jiang Xu,Yizhou Li,Yuanli Liu,Shams Ali Baig,Xinhua Xu
In the present study, carbon black (CB), multi walled carbon nanotubes (MWCNTs), and granular activated carbon (GAC) were employed to support palladium (Pd) catalyst. The prepared Pd/CB, Pd/MWCNTs and Pd/GAC moveable catalysts were aimed to address the common issues (easy loss of catalyst and poor long-term performance) of normal fixed catalysts. The results of various characterizations (e.g., TEM, XRD, and XPS) clearly show that the Pd nanoparticles were successfully loaded onto the carbon-supports, especially CB and MWCNTs. And more importantly, the morphologies, Pd distribution, and chemical structure of these moveable catalysts were almost not changed after 3 h reaction. The moveable Pd/CB, Pd/MWCNTs, and Pd/GAC catalysts had good reactivity for 2,4-dichlorobenzoic acid (2,4-DCBA) dechlorination, and Pd/CB exhibited the best performance. The Pd/CB also shows the best adsorption capacity of 2,4-DCBA and dechlorination product (benzoic acid, BA), and the adsorption of BA was significantly inhibited in the presence of current due to the repulsion between the both negatively charged compounds and adsorbents. The removal of 2,4-DCBA and the generation rate of BA was improved with a pre-adsorption process, which was a promising strategy with higher dechlorination rate and shortened electrolysis time. Moreover, the loss of Pd catalyst was negligible during the 10 consecutive cycles experiment, and the improved longevity could be expected. These results suggested the good reactivity, stability, and reusability of moveable Pd/CB catalyst.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2021
·Vol. 6
·期 3
·465-470
·
IF 4.239
Hang Zhang,Shimin Kang,Jinxia Fu,Yunbing He,Xiangxuan Huang,Jie Chang,Yongjun Xu
Poly(butylene succinate) (PBS), a biodegradable plastic, is expected to have a huge consumer product market in the near future. In this work, PBS was found to be an excellent source of producing valuable tetrahydrofuran (THF), through a solvent-less catalytic hydrogenolysis process over a Pd/C catalyst. A high THF yield, 59.5 wt%, was achieved via a simple one-pot reaction under mild temperature conditions (240 °C). This technique provides a distinctive but important method for the green production of THF from spent PBS.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Hanping Chen,Haoyu Xiao,Sunwen Xia,Danyan Wu,Yingquan Chen,Xianhua Wang,Haiping Yang,Jianjun Xiao
Catalytic hydrotreatment under supercritical ethanol conditions is an effective method for improving the performance of wood tar. In this study, the physicochemical properties of industrial wood tar were characterized, and the hydrotreatment process of wood tar under supercritical ethanol was investigated. In the presence of Pd/C and H2, with the reaction temperature of 320 °C and the reaction time of 3 h, the amount of light component in wood tar increased significantly from 55 to 77 wt %, the ratio of hydrogen to carbon increased, and the oxygen content decreased from 27 to 20 wt %. During the Pd/C catalytic upgrading process, the composition and distribution of light phenols changed obviously. Dimethoxy phenols tended to react to form monomethoxy phenols, and monomethoxy phenols tended to react to form alkylphenols.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Haichuan Zhang,Hui Zhang,Shenglong Tian,Shiyu Fu
In this work, near-complete conversion of lignocellulosic biomass and high products yields were achieved through catalytic transfer hydrogenolysis (CTH) in isopropanol using a heteropoly acid SiW 12 synergistic with Pd/C catalyst at a relatively mild condition. The performances of various heteropoly acids and catalytic conditions were extensively examined. The results confirmed that SiW 12 exhibited the highest activity on disrupting C–C linkages and C-O linkages than H 2 WO 4 , PW 12 , and PMo 12 . 34.91 wt% and 43.55 wt% monophenols were achieved for hydrogenolysis of bagasse and eucalyptus, respectively, at their optimal temperature for 5 h. Characterization studies on the lignin oil revealed that the notable structural changes were observed including the breaking of the side chain alkyl-aryl ether bonds and glycosidic bonds, while methoxyl groups were retained. Additionally, particle size of feedstock also has significant impact on the distribution and yields of the monophenols.
研究领域:
生物化学
·
可再生资源与环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 8
·1827-1835
·
IF 5.2
Zipin Peng,Xuepeng Wang,Zheng Li,Xingkun Chen,Yunjie Ding,Jisong Zhang
Catalytic hydrodechlorination (HDC) is considered to be a safe and effective method to treat chlorinated organic pollutants and has always been a hot spot in basic catalysis research. It is difficult to obtain excellent catalytic performance due to the inferior mass transfer performances of traditional batch reactors, and the deactivation of catalysts can easily occur due to the poisoning effect of HCl. In this work, Pd catalysts supported on activated carbon (Pd/AC) were synthesized by the ion-exchange (IE) method. The characterization results of N2 physisorption, XRD, TEM and XPS revealed that the active Pd components were uniformly dispersed on the surface of AC in the form of nanoparticles. A continuous flow system based on a micro-packed bed reactor (μPBR) was developed for the hydrodechlorination, and the hydrogenation of chlorobenzene (CB) was selected as the model reaction. With the optimal reaction conditions, a conversion and selectivity of 100% were obtained. Importantly, no obvious deactivation of the catalysts was observed during a 100 h time-on-stream test. Moreover, Pd/AC catalysts exhibited remarkable substrate suitability in dechlorination systems. The reaction kinetics for hydrodechlorination of CB in methanol was investigated after the internal and external diffusion limitations were eliminated.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 151
·期 10
·3004-3010
·
IF 3.186
Zhou Junjie,Huang Yu,Shen Jialu,Liu Xiang
The production of H 2 from non-fossil sources is a key research challenge to contributing solving the forthcoming energy problem. Aqueous solutions of tetrahydroxydiboron have very recently appeared as a H 2 source, from which both hydrogen atoms are provided by water, in the presence of highly sophisticated nanocatalysts. Herein, commercial and cheap Pd/C is shown to be an efficient and recyclable catalyst for H 2 evolution upon tetrahydroxydiboron hydrolysis. Graphic Abstract
研究领域:
化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2021
·
IF 2.495
Junjie Zhou,Ning Li,Jialu Shen,Xu Meng,Xiang Liu
Hydrogen has attracted much attention as one of the most promising chemical fuel candidates because of its zero emission during consumption. In order to solve the freezing problem of water based hydrolysis process, herein, the Pd/C as an efficient and stable catalyst for the methanolysis, ethanolysis, propanolysis and butanolysis of B 2 pin 2 for the generation of hydrogen has been first developed. The large kinetic isotope effect (KIE) of k H /k D = 5.0, D 2 formation from CD 3 OD and in situ tandem reaction have confirmed that alcohol is the only hydrogen source. Interestingly, the order of E a of these alcohols in H 2 evolution is MeOH (methanol, 29.57 kJ/mol) < EtOH (ethanol, 34.80 kJ/mol) < PrOH (propanol, 39.08 kJ/mol) < n BuOH (n-butanol, 41.98 kJ/mol), which is consistent with the known order of acidities of these alcohols (MeOH > EtOH > PrOH > n BuOH).
研究领域:
化学
·
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）