Chem Catalysis
·
2022
·
IF 0
Xianhao Zhang,Huijuan Jing,Shiming Chen,Bing Liu,Liang Yu,Jianping Xiao,Dehui Deng
Summary Cyclohexanone oxime (CHO), a key C=N organic compound in the manufacture of nylon 6, is conventionally synthesized via a multistep process that consumes expensive NH 3 and H 2 under harsh conditions. Herein, we report the direct electro-synthesis of CHO from low-cost NO, H 2 O, and cyclohexanone over a carbon catalyst under ambient conditions. A high Faradaic efficiency of 44.8% and a formation rate of 10.7 mg cm −2 h −1 for CHO were achieved at −0.4 V versus the reversible hydrogen electrode through optimizing the surface hydrophobicity of the catalyst to facilitate diffusion of reactants. Controlled experiments and 15 N-labeling tests verified that the nitrogen in the CHO product originates from NO. Density functional theory calculations showed that the armchair edge of carbon could be the active site with a reaction mechanism following NO → NO∗ → HNO∗ → HNOH∗ → NH 2 OH → CHO. This work suggests a direct, green, and low-cost synthesis strategy for high-value CHO from pollutant NO.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
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
ACS Applied Nano Materials
·
2021
·
IF 5.097
Huijing Liu,Yijun Li,Yunling Pan,Jianhui Xie,Bing Li,Zhenguo Guo,Tai-Chu Lau
The development of efficient and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is of current interest. Pyrolysis of 3d metal complexes or mixtures of 3d metal ions and N-containing organic ligands has been found to be an efficient way to afford cost-effective metal- and N-doped carbon electrocatalysts for HER. However, due to the multiple-components nature of the catalysts, it is a challenge to clarify the role of each component. Herein, we report a facile approach to prepare Co- and N-doped carbon catalysts with carbon nanotubes uniformly grafted over the carbon layers via pyrolysis of a Co complex precursor bearing 2,4-diamino-6-pyridyl-1,3,5-triazine ligand. Among the prepared catalysts, Co–N/CNT/C-850 exhibits the best performance as a pH-universal electrocatalyst for HERs, which requires small overpotentials of 120, 190, and 134 mV to achieve a current density of 10 mA cm–2 in 1 M KOH, 1 M phosphate buffer solution (PBS, pH = 7), and 0.5 M H2SO4, respectively. Experimental results and theoretical calculations revealed that the Co2+ dopant played a vital role in tuning the electronic structure of the carbon skeleton, leading to boosted HER catalytic activity of adjacent carbon atoms. Our work should provide insight into the design of metal carbon composites materials for energy conversion.
研究领域:
材料科学
·
电化学
·
理论计算
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Tao Chen,Tingting Ye,Jie Zhu,Guoqing Li,Zhe Chen,Menglin Xie,Yu Zhou,Jun Wang
Metal-free carbon materials have attracted growing attention in terms of green and sustainable catalysis processes that could avoid potential metal leaching but usually suffered from inferior activity to metal-loaded counterparts. In this work, we constructed an efficient carbon catalyst via hydrothermal carbonization of biomass-derived feedstock glucose under relatively low temperature (180 °C). The resultant carbon material possessing abundant surface oxygen species effectively catalyzed the benzene hydroxylation with dioxygen (O 2 ), a desirable but very difficult alternative process for producing the important bulk chemical phenol . A considerably high phenol yield of 13.1% was achieved within 4 h, a reaction time much shorter than all the previous metal-free catalysts and even shorter than most efficient metal-based catalysts. The fast reaction is determined by the formation of small-sized primary carbon particles with the abundant surface oxygen species, for which the adsorption enhancing effect in the media of this heterogeneous process was experimentally evidenced.
研究领域:
催化化学
·
绿色化学
✓ 已验证
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Tongchao Su,Jie Zeng,Haiyan Gao,Liqun Jiang,Xiuzhi Bai,Haixu Zhou,Feixiang Xu
Magnetic carbonaceous acid catalyst was synthesized from nano-Fe 3 O 4 powder, glucose and hydroxyethyl-sulfonic acid by a novel method of one-pot hydrothermal precipitation-sulfonation. It was found that the prepared C-SO 3 H@Fe 3 O 4 /C catalyst had high acidity (1.23 mmol g −1 ) and strong magnetism (12.85 Am 2 /kg). High yields of glucose (62.59%) and total reducing sugar (73.01%) were achieved from NaOH-freeze pretreated sugarcane bagasse by the C-SO 3 H@Fe 3 O 4 /C catalyst at 180 °C in a microwave reactor. In addition, the C-SO 3 H@Fe 3 O 4 /C catalyst could be easily separated and recovered by an external magnetic force at a high recovery rate (93.18%). High yields of glucose (54.47%) and total reducing sugar (60.65%) were also obtained after experiencing five-time cycles. It was demonstrated as an effective hydrolysis of pretreated sugarcane bagasse to fermentable sugars with high yields by the assistance of the C-SO 3 H@Fe 3 O 4 /C catalyst, and the catalyst exhibited an excellent catalytic stability during the conversion process.
研究领域:
生物化学
·
材料科学
✓ 已验证
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Yuechi Che,Xiaopeng Jia,Yongjie Hu,Jian Li,Zhi Wang,Beibei Yan,Guanyi Chen
Tar catalytic removal is a key issue in biomass gasification , which is suffering from catalyst coking and sintering. Microwave technology is attractive due to the high activity on polar molecules and ability to lower activation energy . In this study, the Co/C derived from metal-organic frameworks (ZIF-67) was developed as a bifunctional microwave catalyst that can strengthen the interaction between microwave and tar catalytic reforming , and enhance the anti-coking and sintering ability. The effects of the temperature, heating method, tar concentration, and catalyst support on model tar conversion rate were investigated. The operating conditions at 700 °C and tar concentration lower than 20 g/m 3 can reach a promising conversion rate over 90.15 % under microwave irradiation . On the one hand, microwave heating groups performed better in conversion rate and coking compared to conventional heating, due to the active species generated from the microwave plasma . On the other hand, Co/C showed better performance in catalytic activity and sintering stability, due to the highly dispersion of cobalt nanoparticles and the confinement effect of carbon nanotubes on the catalyst surface . These findings proposed a novel approach for efficient biomass tar removal under microwave irradiation, and offered a potential tool to further reveal the mechanism in microwave driven tar steam reforming system.
研究领域:
能源与环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2012
·
IF 3.832
Keliang Wang,Hui Wang,Sivakumar Pasupathi,Vladimir Linkov,Shan Ji,Ronfang Wang
PtSn nanoparticles deposited on a stable electrocatalytic support containing conventional carbon and palygorskite are prepared using pre-treated palygorskite and are evaluated by ethanol oxidation. The electrocatalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). TEM and XRD show that the pre-treatment has an effective impact on the morphology of palygorskite, but does not destroy its architecture. XPS results imply that introduction of palygorskite can facilitate the formation of Sn oxides on the surface of catalyst. Sn oxides increase the amount of surface oxygen-containing species and in turn facilitate to oxidize CO-like species adsorbed on Pt active sites, which has been proved by CO stripping voltammetry. Cyclic voltammetry (CV) measurements show that the addition of palygorskite into the carbon as support improves the electrocatalytic activity in ethanol oxidation. The developed new composite support is catalytically more active for ethanol electrooxidation than the conventional carbon support and shows good stability, offering great potential for widespread application of palygorskite as support for electrocatalysis.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
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
BULLETIN OF MATERIALS SCIENCE
·
2015
·Vol. 38
·期 5
·1149-1154
·
IF 1.017
DENG TIAN,ZHANG CHONGRONG,XIAO YUYUAN,XIE ANRAN,PANG YUE,YANG YANZHAO
The samarium-doped ceria (SDC) nanospheres were prepared by the one-step hydrothermal method and characterized by transmission electron microscope, scanning electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectrometer and Raman spectra. According to the results, samarium was doped into the lattice successfully. The as-prepared samples were dispersed well and the average diameter was 60 nm. It showed better catalytic performance than pure ceria and the most appropriate concentration of doping was found.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Tengyu Zhang,Meijia Liu,Can Li,Jiwei Zhang,Hui Gao,Fangong Kong,Xuezhang Xiao
Magnesium hydride (MgH 2 ) emerges as a cost-effective and high-capacity hydrogen storage candidate. Despite these advantages, its utilization is constrained by sluggish reaction kinetics and the requirement for elevated operating temperatures. In this study, we aim to address these limitations by investigating the synergistic catalytic effect of yttrium fluoride (YF 3 ) and nickel-loaded nitrogen self-doped porous carbon (Ni/C) as catalysts for MgH 2 . Co-doping with YF 3 and Ni/C reduces the dehydrogenation activation energy to 74.56 kJ/mol, enabling 5.22 wt% H 2 desorption within 5 min at 300 °C. Notably, the system exhibits enhanced low-temperature reaction kinetics, with the MgH 2 -YF 3 + Ni/C composite releasing 5.74 wt% H 2 at 250 °C within 30 min. At 50 °C, the co-doped composite achieves a hydrogen storage capacity of 5.18 wt% within 4 h, whereas the composite with Ni/C only absorbs 3.72 wt% H 2 . Moreover, the MgH 2 -YF 3 + Ni/C shows 98.4 % capacity retention after 30 cycles, indicating excellent reversibility. Mechanistic analysis reveals that the outstanding catalytic performance originates from the synergistic effect among YH 2 /YH 3 , MgF 2 , Mg 2 Ni/Mg 2 NiH 4 , and nitrogen-doped carbon. YH 2 /YH 3 and Mg 2 Ni/Mg 2 NiH 4 act as “hydrogen pump”, providing more active sites for the reaction. Additionally, MgF 2 functions as an electron transfer medium, weakening the Mg-H bond. The introduction of nitrogen self-doped porous carbon improves the dispersion of the catalyst and prevents aggregation, enhancing the dissociation of hydrogen molecules. This work demonstrates a promising strategy for improving the low-temperature hydrogen storage performance of MgH 2 and offers insights into the design of rare-earth fluoride-based catalysts.
研究领域:
材料科学
·
能源化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Hairong Tang,Yong He,Peixi Liu,Jiaming Shao,Fawei Lin,Zhihua Wang
Zeolitic-imidazolate framework precursors (ZIF-67) were synthesized in an inorganic solution with triethylamine as a deprotonating agent for N2O decomposition, and the catalytic activities of the pyrolysis products under different conditions were investigated. Among them, the Co/CoOx@carbon catalyst pyrolyzed at 650 °C in a N2 atmosphere (Co-650N) exhibited excellent low-temperature catalytic activity and stability, achieving 50% decomposition efficiency at 305 °C and ∼100% at 400 °C, which benefitted from its large specific surface area, great reduction performance, abundant cobalt active sites, and surface oxygen species. Further, utilizing temperature-programmed desorption (TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS) results, it was found that N2O molecules preferentially combined with oxygen species bound to cobalt sites. The absorbed N2O was decomposed into N2 and oxygen species, and the latter was subsequently transferred to carbon frameworks. Interestingly, the amorphous graphitic carbon frameworks played an important role in transferring/storing active oxygen and regenerating cobalt sites. Moreover, Co-650N exhibited better resistance to SO2, and the efficiency could be recovered via heating and finally stabilized at 100%. Finally, the mechanisms of N2O decomposition and sulfur poisoning-reactivation on Co/CoOx@carbon catalysts were proposed for the first time.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）