ACS Applied Energy Materials
·
2018
·
IF 0
Zhongliang Ma,Jiguang Zhang,Yunfeng Zhu,Huaijun Lin,Yana Liu,Yao Zhang,Delong Zhu,Liquan Li
Metal nanocatalysis is an effective method to enhance the hydrogen storage properties of magnesium hydride (MgH2), and the catalytic effect can be further improved by a matrix material supported nanometal. In this work, carbon supported nano-Ni (Ni@C) was synthesized by calcination of dimethylglyoxime dinickel chelate, and then it was doped into MgH2 to improve the de/rehydrogenation kinetics. This shows that the homogeneously distributed Ni with refined particle size in carbon base leads to superior catalytic effects on hydrogen absorption/desorption of MgH2-5 wt % Ni@C. The MgH2-5 wt % Ni@C starts to desorb hydrogen at 187 °C, which is 113 °C lower than that of as-milled MgH2. Moreover, it takes only 500 s to thoroughly desorb hydrogen at 300 °C, which is 3000 s faster than as-milled MgH2 under the same dehydrogenation conditions. According to the Kissinger’s method, the apparent activation energy for desorption of the MgH2-5 wt % Ni@C is 66.5 ± 1.8 kJ mol–1, which is about 79.9 kJ mol–1 lower than that of as-milled MgH2. Cycling experiments show that the capacity retentions of hydrogen absorption and desorption after 10 cycles at 275 °C are 91% and 93%, respectively. Transmission electron microscope analysis shows that part of Ni transformed to Mg2NiH4/Mg2Ni during hydrogen absorption/desorption cycles.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Yuzhou Xue,Zhenchao Lei,Wenxiao Zheng,Weijian Duan,Liuyi Zhu,Zhang Yan,Chunhua Feng
It is generally known that carbon supports with a large surface area are essential for dispersion of Pd catalysts and adsorption of pollutants (e.g., chlorinated compounds), thus enabling enhanced mass transfer and increased reaction kinetics. However, we demonstrate that, in spite of contributing to achieving highly dispersed Pd nanoparticles , a high-surface-area carbon support favoring fast adsorption of 2,4-dichlorophenol negatively impacts the catalytic activity of Pd. Comparisons of catalytic performance between Pd/activated carbon (AC) catalysts with different mass loadings in a 3D electrochemical dechlorination reactor suggested that Pd(60%)/AC outperformed Pd(10%)/AC, although the latter had smaller Pd catalysts and the amount of Pd was same in these experiments. We found that the dechlorination rate constant was inversely correlated to the adsorption rate constant at Pd loadings from 10% to 60%. We further verified that the use of C 3 N 4 , an optimal carbon support with low surface area that allows good dispersion of Pd nanoparticles (10%), is critical in accelerating the dechlorination reaction kinetics due to the improved accessibility of active sites to the pollutants. This study provides information on how to select optimal supporting materials with desirable features that avoid catalyst aggregation and pre-adsorption of pollutants when the supported Pd catalysts are used as the moveable particle electrodes.
研究领域:
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
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 15
·2395-2401
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IF 3.741
Mei He,Sheng Qu,Wu Huimin,Zhang Xiuhua,Wang Shengfu,Xia Qinghua
Alloy nanoparticles of the type Pt x Fe (where x is 1, 2 or 3) were synthesized by coreduction with sodium borohydride in the presence of carbon acting as a chemical support. The resulting nanocomposites were characterized by scanning electron microscopy and X-ray diffraction. The nanocomposite was placed on a glassy carbon electrode, and electrochemical measurements indicated an excellent catalytic activity for the oxidation of glucose even a near-neutral pH values and at a working voltage as low as 50 mV (vs. SCE). Under optimized conditions, the sensor responds to glucose in the 10.0 μM to 18.9 mM concentration range and with a 3.0 μM detection limit (at an S/N ratio of 3). Interferences by ascorbic acid, uric acid, fructose, acetamidophenol and chloride ions are negligible.
Nonenzymatic sensing of glucose is demonstrated at neutral pH values and low working potential using a glassy carbon electrode modified with platinum-iron alloy nanoparticles on a carbon support.
研究领域:
生物化学
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材料科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Feng Jiang,Shanshan Wang,Jiao Zheng,Bing Liu,Yuebing Xu,Xiaohao Liu
Promoters, such as Na and Mn, play an important role in governing the active phase and catalytic performance of cobalt-based FTS catalyst. In this work, the dependence of the promotional effect of promoters on supports has been investigated by using the carbon and silica supported cobalt-based catalysts in the presence of Na, Mn, and both Na and Mn promoters, respectively. The characterization results of H 2 -TPR, CO-TPD and XRD profiles together with the FTS performances demonstrate the strong dependence of the promotional effect of promoter on the type of support used. The carbon support, which shows weak cobalt-support interaction, facilitates the manifestation of the effect of promoter. In detail, Mn can promote the formation of Co 2 C sites at the conditions of 260 °C, 0.5 MPa and lower H 2 /CO ratio, resulting from the promoted CO adsorption and subsequent dissociation. Thus, the suppressed adsorption of H 2 and the promoted surface dissociative C* concentration enhances the selectivities to lower olefins (C 2 = -C 4 = ) and C 5+ with a decrease in methane selectivity. Interestingly, the further addition of Na promoter shows synergistic effect of Na and Mn promoter on remarkably increasing selectivity to lower olefins due to the obviously suppressed chain growth. This synergistic effect could be observed only at the weak cobalt-carbon interaction with a more obvious effect at lower H 2 /CO ratio in feed gas that favors the increase of Co 2 C sites with mainly exposed facets of (111) and (020). The presence of (020) facet might be more crucial to enhance the formation of lower olefins. However, over silica support with strong cobalt-silica interaction, the promotional effect of Mn is obviously suppressed, which leads to only CoO and metallic Co sites in the FTS reaction and much weaker impact on product selectivity. The further addition of Na into Mn-promoted cobalt catalysts shows similar effect as Na promoter alone in the product selectivity where the chain growth is highly promoted to remarkably suppress methane selectivity and enhance selectivity to C 5+ rather than desired lower olefins. In contrast to carbon support, the strong cobalt-silica interaction leads to less promotional formation of CO 2 via the Boudouard reaction (2CO*→C* + CO 2 ) due to the increased non-dissociative adsorption of CO.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·Vol. 40
·期 4
·753-760
·
IF 3.1
Li Jinrong,Yu Xianghui,Sun Qi,Peng Yong,Cao Shuang,Hou Chun-Chao,Xu Qiang
PtCo nanoalloys (NAs) deposited on carbon black are emerging as robust electrocatalysts for addressing the sluggish kinetic issue of oxygen reduction reaction (ORR). However, developing a simple and low-cost method to synthesize PtCo/C with excellent performance is still a great challenge. In this work, a one-pot method was used to successfully obtain the PtCo NAs on commercial carbon supports of acetylene black and Ketjenblack ECP600JD, respectively. Compared with those grown on Ketjenblack ECP600JD, the PtCo NAs grown on acetylene black exhibited higher electrochemical surface area (ECSA) and mass activity (MA), which may be attributed to the different particle sizes of PtCo NAs, distinct hydrophilicity, electroconductivity and charge distribution between the carbon supports and PtCo NAs. Our study provides valuable insights into the optimal design of carbon-supported ORR electrocatalysts with exceptional activity and durability.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2025
·Vol. 11
·期 10
·
IF 12.5
Zhongliang Huang,Qi Xiao,Tianyi Ding,Jing Xia,Changhong Zhan,Xiangmin Meng,Chih-Wen Pao,Zhiwei Hu,Wei-Hsiang Huang,Yingru Wang,Nanjun Chen,Liang Cao,Xiaoqing Huang
Platinum (Pt) has been documented as the top-tier fuel cell catalyst, yet it faces a notable challenge regarding its poor CO tolerance and sluggish oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs), particularly when using CO-contaminated blue and gray H2. Here, we present an interfacial metal coordination strategy to design a bifunctional platinum-cobalt (PtCo) intermetallic catalyst integrated with a tin-nitrogen-carbon (Sn–N–C) support, which forms Pt–Sn–N bonds that substantially boost both ORR activity and CO tolerance. The PtCo/Sn–N–C-made fuel cell achieves a topmost peak power density of 2.11 watts per square centimeter in 100 parts per million (ppm) of CO-containing H2, surpassing all previously reported PEMFCs. In addition, it operates stably at a rated voltage for over 710 hours in 100 ppm of CO/H2-air. This work demonstrates the feasibility of fuel cells directly using CO-contaminated gray & blue H2, paving the way for PEMFC-driven energy vehicles.
研究领域:
材料科学
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能源工程
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）