Plasma Processes and Polymers
·
2020
·Vol. 17
·期 12
·2000072
·
IF 3.065
Xueli Hu,Xinbo Zhu,Xiqiang Wu,Yuxiang Cai,Xin Tu
In this study, plasma-enhanced NH 3 synthesis over a series of M/AC (M = Ru, Co, Ni, and Fe) catalysts was investigated. The combination of the plasma and activated carbon (AC) enhanced the reaction performance compared with the reaction using plasma alone. The doping of active metal on AC further improved the reaction performance by up to 37.3%. The highest NH 3 concentration of 3,026.5 ppm was obtained over Ru/AC at a specific input energy (SIE) of 12.5 kJ/L, followed by Co/AC, Fe/AC, and Ni/AC. The highest energy efficiency of 0.72 g/kWh was achieved at an SIE of 8.0 kJ/L when using the Ru/AC catalyst. Catalyst characterizations showed that the basicity of the M/AC catalysts plays an important role in the plasma-enhanced catalytic synthesis of NH 3 . The reaction mechanism in the plasma-enhanced NH 3 synthesis was also discussed.
研究领域:
催化化学
·
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2018
·
IF 1.372
Yuanyuan Ding,Jianhong Yang,Jun Cai
Guanidinylated carboxymethyl chitosan (GCMCS) was prepared via the guanidinylation of carboxymethyl chitosan (CMCS). A device employing the diffusive gradients for thin films (DGT) technique was made using a GCMCS aqueous solution as the binding agent and a cellulose acetate dialysis membrane (CADM) as the diffusion phase to measure labile Cu2+, Pb2+ and Cd2+ in water. The percentage uptake (U%) values of labile Cu2+, Pb2+ and Cd2+ in a synthetic water sample were almost consistent with the theoretical values at 101.6 ± 2.8%, 104.6 ± 6.1% and 95.9 ± 4.4%, respectively. The optimum pH ranges for the measurement of labile Cu2+, Pb2+ and Cd2+ were 3.0–7.0, 3.0–7.0 and 4.0–8.0, respectively. The ionic strength mainly affected the diffusion of metal ions in the CADM. The diffusion rates decreased with increasing concentrations of NaNO3 solutions. The application of GCMCS-DGT in natural water and industrial wastewater showed that dissolved organic carbon (DOC) only affects metal species, and the accurate determination of labile Cu2+, Pb2+ and Cd2+ can be achieved when the diffusion coefficients of these metal ions in the diffusion phase have been determined. GCMCS is suitable for DGT application as a chelating agent for metal ions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 110
·109023-109029
·
IF 3.289
Lijuan Lan,Fanglin Du,Chuanhai Xia
Carbon nanotubes (CNTs) supported Pd catalysts (1 wt% and 5 wt%) were prepared by a conventional impregnation method and tested in liquid-phase hydrodechlorination (HDC) of para-chlorophenol (p-CP) under mild conditions (313 K and atmospheric pressure) with H2. CNTs as a catalyst support offered better performance than activated carbon (AC). The conversion of p-CP reached 72% and 82% over 5 wt% Pd/AC and 5 wt% Pd/CNTs, respectively, within 30 min. When the content of Pd was reduced to 1 wt%, the conversion of p-CP over Pd/AC and Pd/CNTs was 55% and 83%, respectively. The mechanism of this phenomenon was studied through catalyst characterization (XRD, TEM, and BET). The abovementioned results indicated that the different activities of the catalysts over different supports mainly resulted from the porous structure of the supports and nanoparticle diameters of the active metal.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Dan Luo,Yurong He,Xin Yu,Fei Wang,Jiaojiao Zhao,Wentao Zheng,Haijun Jiao,Yong Yang,Yongwang Li,Xiaodong Wen
For the catalytic reductive amination of carbonyl compounds , the kind of active metal used is the most important factor determining the catalytic selectivity in heterogeneous catalysis systems. However, a detailed understanding of the intrinsic mechanism is still lacking. In this work, by evaluating the reductive amination of butyraldehyde and the hydrogenation reaction of secondary imine on various metal catalysts, the competitive hydrogenation reactions of primary imine and secondary imine are proven to be the key factors determining primary amine selectivity. DFT calculations verify that Co, Ni, and Ru, rather than Fe, Rh, Pd, and Pt, tend to show high primary amine selectivity in terms of adsorption energy and activation energy. It should be noted that the different stable adsorption modes of secondary imine on metal surfaces (C&N adsorption mode on Fe, Co, Ni, Ru, and Rh, and N adsorption mode on Pd and Pt) are key factors affecting these reaction characteristics. Moreover, microkinetic simulation proves that the coadsorption of NH 3 improves primary amine selectivity on Co, Ni, and Ru surfaces. Combining the theoretical and experimental results, it is clearly verified that the active metal determines the catalytic selectivity of the primary amine by affecting the competitive hydrogenation reactions of the primary imine and secondary imine.
研究领域:
催化化学
·
材料科学
·
理论计算化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 10
·727
·
IF 3.8
Jie Fan,Wei Li,Jingyi Yang,Tao Yang,Zhongyi Liu,Meng Zhang
With the rapid development of modern society, the consumption of fossil fuels during the industrial production process produces a significant amount of carcinogens. Converting the highly toxic biphenyl (BP) to the valuable product cyclohexylbenzene (CHB) can decrease the emission of carcinogenic aromatic hydrocarbons. In this study, we prepared a series of 20%Ni/SiO2catalysts with different specific surface areas (SSAs) using the over-volume impregnation method, as well as 20%M/SiO2(M = Fe, Cu, Co, and Ni) catalysts to highlight the effects of support SSAs and active metal on the performance of BP selective hydrogenation to CHB. The catalysts were characterized by XRD, N2physisorption, TEM, and H2-TPR, which demonstrated that a high SSA would be helpful for the dispersion of the active metal. The evaluation results revealed that 20%Ni/SiO2-300 exhibited excellent activity and stability in the selective hydrogenation of BP to CHB (BP conversion: 99.6%, CHB yield: 99.3% at the conditions of 200 °C, 3 MPa, 4 h and isopropanol as the solvent) among the catalysts with different SSAs, which was also superior to the performance over the catalysts with other transition metals as the active sites. The structure–activity relationship of the employed catalysts for the selective hydrogenation of BP to CHB was also discussed.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Fu Yang,Jin Wang,Shuying Gao,Shijian Zhou,Yan Kong
Herein, we report an excellent in-situ exsolution triggered hydrogenated catalyst F-Ni/Cu-P-RT started from bimetallic phosphate Ni/Cu-P-RT, affording an ultrafast catalytic hydrogenated rate (20 s even 5 s) in nitrophenol reduction. In the first catalytic cycle, we proved the enhanced catalytic reduction activity of bimetallic Ni/Cu-P-RT within 50 s compared to monometallic counterparts. The kinetics results revealed Ni/Cu-P-RT affords the reaction rate K of 2.85/4.23/6.6 min −1 at 20, 30, and 40 °C with the activation energy 32 kJ/mol. Impressively, the involved reaction induction period is visibly observed and interpreted by reconstruction and evolution of active metal during the reaction, but was eliminated through integrating two metal Cu-Ni by regulation of electronic band energy of phosphate from 4.1–3.5 eV. The nascent Cu and Ni nanoparticles as reaction-preferred active species were in-situ exsolved partially after adding NaBH 4 , triggering the resulted higher active and stable F-Ni/Cu-P-RT(20 s, 14.1 min −1 ) in later multiple cycles.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 5
·2848-2853
·
IF 3.361
Xiaoliang Ren,Shufang Wang,Xiaoshu Ding,Dongsheng Zhang,Yanji Wang
In the chemical industry, reactors are typically designed and filled with supported catalyst particles. However, the intrinsic problems associated with the internal/external diffusion effect and catalyst separation/loss in these traditional reactors can be very challenging to mitigate. To address these issues, herein, an active metal sintered membrane reactor anchored with Pt atoms was successfully developed, and applied into continuous, liquid-phase, hydrogenation processes. The catalyzing reactions transpired on the active sites that were fastened onto the surface of the reactor's microchannels. As a result, the mass transfer at the gas–liquid–solid three-phase was greatly enhanced, and an incredibly high reaction efficiency was obtained. The novel, active reactor demonstrated a superior catalytic performance and stability to nitrobenzene (NB) hydrogenation at 120 °C and 0.5 MPa H2, which enabled an aniline (ANI) yield of 19.28 molANI h−1 L−1. This work opens a new window for the design of high-performance gas–liquid–solid reactor toward multiphase catalytic reactions.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Jiangyong Yuan,Chunqiang Lu,Zhenhua Gu,Jun Cai,Han Zhao,Danyang Li,Lei Jiang,Haiwen Xu,Zhi qiang Li,Kongzhai Li
Carbon cycling, instead of conventional oxygen cycling in chemical looping, overcomes the limitations of oxygen storage capacity of oxygen carriers and enables the reaction to proceed under relatively mild conditions. In this study, we designed a high-performance carbon-storage catalyst (Ni-Co/Al 2 O 3 ) for chemical looping conversion of CH 4 and CO 2 to H 2 and CO. The physico-chemical characterizations suggested that the Co alloyed with Ni could result in larger active metal particles and simultaneously benefit the bending of carbon deposits toward the periphery of the active sites, avoiding the quick deactivation of catalysts due to the encapsulation of the active sites by carbon deposits and generating a higher carbon capacity (23.59 vs. 14.08 mol/kg). In addition, the alloying of Co with Ni could weaken the graphitization of carbon deposits, thus facilitating the carbon elimination and catalyst regeneration in the CO 2 conversion step, strongly improving the cycling stability during long-term testing.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Jun-Yang Yan,Gui-Ping Cao,Chun-Yan Cao,Peng Gao,Mustapha Sani Shehu,Hui Lv,Alaaddin M. M. Saeed
This work investigated the loading of active metals on monolithic carrier NCNTs@FN through simulation and characterization and found that the active metal (Pd) had a stronger binding with NCNTs and a more uniform dispersion. Meanwhile, the π–π stacking effect between NCNTs and polystyrene (PS) molecules is more significant than that between PS and CNTs, making PS more easily adsorbed. Therefore, the highly active catalyst Pd-NCNTs@FN was prepared. The hydrogenation degree of Pd-NCNTs@FN catalyzed PS reached 92.7%, significantly higher than that of Pd-CNTs@FN (78.1%) under the same conditions. Uniform experiments on PS hydrogenation kinetics were designed. Power law and hyperbolic kinetic models were established, and the corresponding parameters were calculated. From the models, it was found that whether H2 concentration reaches a critical value determines whether H2 pressure affects the hydrogenation rate. In addition, the adsorption of PS is the rate control step in the reaction. The activation energy of Pd-NCNTs@FN catalyzed PS hydrogenation is 47.326 kJ/mol, which is lower than those of other traditional powder heterogeneous catalysts (50–55 kJ/mol), demonstrating the excellent activity of the catalyst.
研究领域:
催化化学
·
材料科学
·
反应动力学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zhi Yang,Bowen Luo,Riyang Shu,Zhuojie Zhong,Zhipeng Tian,Chao Wang,Ying Chen
Hydrodeoxygenation (HDO) is an indispensable reaction in the field of fuel and chemical production, and the synergistic effect of metal–acid sites in the catalyst makes great influence to it. Herein, a bifunctional catalyst of Ru/C combined with phosphotungstic acid (HPW) was employed for the hydrodeoxygenation (HDO) of lignin-derived compounds to make full use of the synergistic effect of active metal–acid sites. HPW possessed a temperature-controlled phase-transfer behavior, which made it dispersed well on the surface of Ru/C catalyst and resulted in a close integration of acid site with metal site. Ru/C-HPW catalyst also owned the advantage of high reaction rate and good recyclability, which exhibited no obvious catalytic activity loss after 5 runs. Lignin-derived phenolic compounds including monomers and dimers enabled to obtain an efficient transformation to cycloalkanes at the temperature of 200 °C. Moreover, a high HDO reaction efficiency of raw lignin-oil was also observed in this study, with the increasing hydrocarbon content from 5.5% to 78.9%. This novel catalytic system can achieve a high HDO efficiency under mild conditions.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Small Methods
·
2025
·
IF 9.1
Yaping Wang,Tingshi Zhang,Xinlian Huang,Yurong Zeng,Siyuan Wei,Zanyong Zhuang,Chongbing Zhu,Yan Yu
Herein, a versatile amorphous-to-crystalline transformation (ACT) strategy is described, to furnish various metals (Cu, Co, Ni, Cs, and Y) based atomically dispersed catalysts (ADCs) on thin holey 2D Al 2 O 3 . This approach, which involves adjusting reactant stoichiometry, enables the continuous modulation of particle size of ADCs at an atomical level, giving the ultrafine products as single atom, cluster, or nanoparticle catalysts. This synthesis method allows a straightforward analysis and comparison of the reactivity of the ADCs catalysts based on the dispersion of the active metal. In the case of Cu, the cluster catalyst 0.2-Cu/Al 2 O 3 outperforms the single atom catalyst 0.1-Cu/Al 2 O 3 and the nanoparticle catalyst 0.3-Cu/Al 2 O 3 in the oxidation of refractory organic molecules, thanks to its superior electron transport and surface adsorption properties. These findings are well supported by the Density functional theory (DFT) calculations. Additionally, this method facilitates the preparation of atomic clusters with a very small size of 0.5–1 nm, composed of just a few atoms, as exemplified by Ni-based ADCs. The developed synthesis enriches the library of ADCs and demonstrates the potential of amorphous-to-crystalline transformation in creating advanced ultrasmall functional materials.
研究领域:
材料科学
·
催化化学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DENTAL MATERIALS
·
2025
·
IF 6.3
Zhao Li,Ying Kong,Qun Zhang,Jing Han,Kezheng Chen,Baojin Ma
Traditional guided bone regeneration (GBR) membranes face challenges in balancing mechanical strength, bioactivity, and osteoconductivity for effective periodontal bone regeneration. While collagen-based GBR membranes dominate clinical use, the weak mechanical properties and lack of osteoinductive capacity limit regeneration efficacy. Here, we presented a gas diffusion-mediated single-sided mineralization strategy to fabricate silk fibroin (SF)-based GBR membranes with dual barrier/osteoinductive functions. SF was dissolved in formic acid with Ca 2 + and, optionally, other bioactive metal ions (BMIs, such as Sr 2+ , Cu 2+ , or Mg 2+ ), and a colloid was formed after the evaporation of formic acid. Followed by gradient mineralization under CO 2 /NH 3 atmosphere and β-sheet induction via ethanol treatment, SF-Ca/X (X refers to other BMIs) membranes were prepared. Mineralized SF membranes featured a dense, mineral-free side for mechanical support and barrier, and an osteoinductive side by releasing BMIs. Interestingly, the calcium phosphate layer formed on the mineralized side, and the phase of CaCO 3 changed from calcite to vaterite, which helps phosphate mineralization. In vitro results demonstrated that the SF-Ca/Sr membrane enhanced osteogenic differentiation by upregulating BMP2/SMAD1 expression. In a rat mandibular defect model, the SF-Ca/Sr membrane significantly promotes new bone regeneration and collagen formation. Overall, this gas diffusion-mediated single-sided gradient mineralization approach integrates barrier properties with localized bioactivity, allowing for the required barrier/osteoinduction functions in the GBR process in one membrane.
研究领域:
生物材料学
·
组织工程
·
口腔颌面外科
·
再生医学
·
生物矿化
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）