Molecular Catalysis
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2024
·
IF 3.9
Pengcheng Wang,Qingqing Jiang,XingYu Li,Xuedong Wang,Juncheng Hu
Generally, researchers focus on the regulation of metal sites rather than surrounding nonmetals in photothermal CO 2 hydrogenation reaction. Herein, concerning the role of non-metallic N species, a series of Co/NC-T catalysts have been fabricated via high-temperature pyrolysis of Zeolitic Imidazolate Frameworks-67. The CO 2 conversion rate shows a consistent tendency with the ratio of graphitized-N species while the product selectivity is closely related to the coordination state of Co-N x species. Co/NC-800 catalyst achieves high CO 2 conversion rate of 758 mmol g cat -1 h -1 with CH 4 selectivity of 99.6 %. After adding extra graphitized-N species, the CO 2 conversion rate could further enhance to 80.2 % for N-Co/NC-2. The role of N species in photothermal CO 2 hydrogenation reaction has been investigated in details, providing new insights for the design of metal organic frameworks derived metal/N-doped carbon catalysts.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
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IF 8.328
Jianqing Ma,Qunfeng Yang,Yuezhong Wen,Weiping Liu
Heterogeneous Fe-N complexes are a kind of promising catalysts for the Fenton-like reaction. The present study selected a stable and inexpensive g-C 3 N 4 as the chelating agent and combined with the graphitized mesoporous carbon (GMC). The fabricated Fe-g-C 3 N 4 /GMC composite was characterized by several techniques including FTIR, XRD, XPS, TEM and STXM. Results showed clear sheets of g-C 3 N 4 and graphite with Fe evenly distributed mostly in the Fe-N coordination form. The catalyst expressed high activity in the Fenton-like reaction in a wide pH range of 4–10. 99.2% removal of Acid Red 73 was obtained in 40 min, and the degradation data well fitted with the pseudo-first-order kinetics model. By correlating the constant of reaction rates calculated from the model and the Fe speciation contents of the samples prepared at different conditions, we deduced that Fe-N species are the most important active sites for the Fenton-like reaction. More importantly, hydroxyl radicals played a great role in the whole reaction yet their generation was independent of visible light. Cyclic voltammetry results confirmed that the GMC can accelerate the Fe(III)/Fe(II) redox cycle by enhancing electron transfer, and thus enable this Fenton-like catalyst to perform well in a wide pH range.
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
FUEL
·
2024
·
IF 6.7
Jing Li,Xiaorui Yan,Yujing Ren,Tiantian Liu,Kairui Li,Haisheng Wei
Design of metal Co-based catalysts by different strategies has aroused many attentions in the chemoselective hydrogenation of nitroarenes to improve their catalytic performance. Herein, Co(6)-N-C catalyst with highly dispersed metal Co and Co-N species was synthesized by the assistance of formed Zn species, which exhibits better performance than single atom Co catalyst in the selective hydrogenation of 3-nitrostyrene, in which the increasing of hydrogenation activity is usually accompanied by unsatisfactory selectivity. In this work, Co(6)-N-C catalyst obtains 98.5 % conversion and > 99 % selectivity of 3-vinylaniline, as well as excellent cyclic stability and desirable substrate universality for the hydrogenation of other substituted nitroarenes. It is demonstrated that the good performance is ascribed to the synergy of metallic Co and Co-N species in the Co(6)-N-C catalyst, improving the activity and selectivity. This work provides a novel strategy to construct an efficient Co-based catalyst for enhanced hydrogenation performance.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2020
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IF 12.35
Shangbo Ning,Hua Xu,Yuhang Qi,Lizhu Song,Qiqi Zhang,Shuxin Ouyang,Jinhua Ye
The transformation of CO2 into a single product is a critical scientific challenge because of the difficulty associated with targeted activation and conversion of CO2 by heterogeneous catalysts. Herein, we present an atomic-scale dispersed Co–N species anchored Co@C hybrid structure (entitled as Co@CoN&C) that regulates catalytic properties in thermodynamic and kinetic processes to achieve active and highly selective CO yield in the photothermal CO2 reduction. An optimal sample delivers the maximum yield rate of 132 mmol gcat.–1 h–1 and remarkable CO selectivity (91.1%), while the undesirable methanation activity, compared with typical Co nanoparticles (NPs), was suppressed. The mechanism study suggests that the strong photon–matter interaction over graphitic-carbon and Co NPs can enhance the light-to-heat conversion efficiency and thus induce the high work temperature, which is thermodynamically beneficial for CO2 activation and subsequently promoted the catalytic activity. Furthermore, the carbon layers improve the adsorption of CO2, and the surface atomically dispersed Co–N species weakens hydrogenation capability, which kinetically controls the reaction pathway and therefore attains the high selectivity for CO production. This study exemplifies that the microstructure design can modulate the thermodynamic and kinetic factors of photochemical reaction and thereby achieve potential solar-to-chemical energy conversion.
研究领域:
材料科学
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催化化学
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能源转换
✓ 已验证
产品关联
DOI
高影响因子
Science China-Materials
·
2022
·Vol. 66
·期 1
·169-178
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IF 8.64
Wei Haisheng,Song Huaxing,Ren Yujing,Yan Xiaorui,Fang Geqian,Wang Wenhua,Ren Wanzhong,Zhu Mingyuan,Lin Jian
Metal-organic frameworks (MOFs) derived Co-based catalysts have received extensive attention in the chemoselective hydrogenation of nitroarenes, while they usually require a lot of solvent during the synthesis and identification of active species. This study explores a solid-phase synthesis strategy to obtain MOF precursors without using any solvent, which is then foamed and pyrolyzed to synthesize the Co@NC-X catalyst. It was found that a nitrogen-doped graphene shell can well encapsulate the Co nanoparticles. The resulting catalyst, which was pyrolyzed at 800°C, exhibited ~100% conversion for the hydrogenation of 3-nitrostyrene and >99% selectivity to 3-vinylaniline. This catalyst also showed excellent stability and good substrate universality for the hydrogenation of extensive substituted nitroarenes. Various characterizations revealed a positive relationship between the catalytic performance and the content of Co—N species tuned by pyrolysis temperature. This work provides a novel and green strategy to design an efficient Co-based catalyst for chemoselective hydrogenation.
研究领域:
催化
·
材料科学
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化工
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绿色化学
✓ 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）