INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2019
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IF 4.084
Yinghui Sun,Guojie Zhang,Ying Xu,Riguang Zhang
The nitrogen doped activated carbon (AC-N) has been successfully prepared with commercial activated carbon as carbon material followed by a simple N-doping method using melamine as nitrogen sources. Using AC-N as the supports, cobalt supported on N-doped activated carbon (Co/AC-N) were developed and used as catalyst for dry reforming reaction (DRM). It was discovered that the Co/AC-N catalysts revealed much higher catalytic performance for DRM reaction in comparison to activated carbon supported cobalt catalyst (Co/AC). Moreover, the catalytic activity was influenced by preparation conditions of AC-N such as calcination temperature and the doping amount of nitrogen. The catalysts were characterized by BET, XRD , XPS , H 2 -TPR, Raman spectroscopy and TEM. It was found that catalytic activities of the catalysts with different calcination temperature and nitrogen doping were influenced by catalyst surface defects and disorders, Co 2+ /Co 3+ molar ratio , the content of nitrogen function groups (graphitic N, pyrrolic-N and pyridinic-N) and interaction between active metal and support. The Raman spectroscopy illustrated that the N-doped catalyst surface defects and disorders increased, which improved the performances of the Redox catalysts. The XPS valence band also revealed that higher Co 2+ /Co 3+ molar ratio and nitrogen function groups was achieved by decreasing calcination temperature and increasing nitrogen doping. In short, the doping of nitrogen increased the structural defects and the interaction between active metals and supports, modified the surface electronic structure, which were facilitated the oxidation and reduction of methane and carbon dioxide.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
·
IF 5.816
Qiangqiang Xue,Zhengwen Li,Zhao Jiang,Meng Chen,Yujun Wang,Binhang Yan,Guangsheng Luo
Steam reforming (SR) is a process for converting transportation fuels into hydrogen-rich gas, which can be fed to SOFCs for on-board power supplies. Herein, we prepare Mg x Ni 1-x O (0.5
研究领域:
能源化学
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
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2021
·
IF 4.126
Bei-Bei Xu,Xiao-Meng You,Jing-Xian Dong,Xue-Lu Wang,Ye-Feng Yao
The nanoparticle size and crystal facet structure of supported noble-metal photocatalysts are two critical factors affecting their activity and selectivity in alcohol reforming processes. Moreover, these effects are often intertwined and remain poorly understood at a fundamental level owing to the complexity of the reaction conditions at the solid–liquid interface. This is addressed in the present work by applying an operando 1H nuclear magnetic resonance spectroscopy method to investigate the detailed relationships between the nanoparticle size and facet structure of supported Pt graphitic carbon nitride photocatalysts and the selectivity and reaction rates of methanol and ethanol reforming products. The results demonstrate that relatively small Pt nanoparticles with no discernible Pt(111) crystal facets have high selectivity and efficiency for producing reforming products with a low degree of polymerization (e.g., aldehydes, hemiacetals, and acids), while relatively large nanoparticles with obvious Pt(111) crystal facets tend to produce reforming products with an increased degree of polymerization (e.g., acetals, ethers, and esters). The results clearly demonstrate that the degree of polymerization and the reforming pathways for methanol and ethanol molecules can be adjusted effectively by manipulating the size and crystal facets of the supported Pt nanoparticles, and these effects may be generally applicable to more complex alcohols of the form CH3(CH2)nOH (n > 1).
研究领域:
催化化学
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材料科学
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表面科学
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
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2025
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IF 9.1
Shanshan Shao,Zixuan Huang,Xiaohua Li,Weicheng Wang,Shiliang Wu
In this study, the impact of pre-reforming procedure on the intermediate products and the production of hydrogen in the two-stage steam reforming of bio-oil generated from pine sawdust was explored. The evolution of the intermediate products in the liquid and gas phase affected by the pre-reforming catalyst (red mud, dolomite, biochar) and pre-reforming temperature was investigated, as is impact of intermediate products on the hydrogen production. The findings indicate that dolomite was identified as the most effective pre-reforming catalyst due to its high CaO/MgO content, which promoted the Boudouard reaction more effectively than the Fe 2 O 3 in in red mud. Low-temperature pre-reforming (≤450 °C) was more beneficial than high-temperature pre-reforming (≥550 °C) at which coke precursors, including aromatic hydrocarbons and phenols were easily produced, leading to rapid catalyst deactivation. Liquid-phase intermediates were primarily composed of furans, phenols, and ketones, with ketones accounting for up to 55.63 %, which may be related closely to the greatly promoted ketonization by the alkaline Ca(OH) 2 produced via the combination dolomite and water at low temperature. Ketones were actually more favorable to the second-stage reforming over Ni-based catalysts, and the ultimate hydrogen yield reached 66.52 %. Due to the low inclusion of phenol and aromatic hydrocarbon intermediates less susceptible to carbon deposition, the catalyst could be more stable. The two-stage steam reforming of pyrolysis bio-oil can avoid catalyst deactivation and enhance the hydrogen production to a higher degree, accomplished by changing the intermediates components with varied pre-reforming catalysts and temperatures.
研究领域:
能源化学
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催化科学
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生物质转化
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氢能源
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反应工程
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Environmental Science & Engineering
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2022
·Vol. 17
·期 3
·1-12
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IF 6.048
Gao Yuchen,Jiang Jianguo,Meng Yuan,Ju Tongyao,Han Siyu
Biogas is a renewable biomass energy source mainly composed of CH 4 and CO 2 . Dry reforming is a promising technology for the high-value utilization of biogas. Some impurity gases in biogas can not be completely removed after pretreatment, which may affect the performance of dry reforming. In this study, the influence of typical impurities H 2 S and NH 3 on dry reforming was studied using Ni/MgO catalyst. The results showed that low concentration of H 2 S in biogas could cause serious deactivation of catalyst. Characterization results including EDS, XPS and TOF-SIMS confirmed the adsorption of sulfur on the catalyst surface, which was the cause of catalyst poisoning. We used air calcination method to regenerate the sulfur-poisoned catalysts and found that the regeneration temperature higher than 500 °C could help catalyst recover the original activity. NH 3 in the concentration range of 50–10000 ppm showed a slight inhibitory effect on biogas dry reforming. The decline rate of biogas conversion efficiency increased with the increase of NH 3 concentration. This was related to the reduction of oxygen activity on catalyst surface caused by NH 3 . The synergetic effect of H 2 S and NH 3 in biogas was investigated. The results showed that biogas conversion decreased faster under the coexistence of H 2 S and NH 3 than under the effect of H 2 S alone, so as the surface oxygen activity of catalyst. Air calcination regeneration could also recover the activity of the deactivated catalyst under the synergetic effect of H 2 S and NH 3 .
研究领域:
能源化学
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催化化学
✓ 已验证
DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 6
·606
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IF 4.501
Yadong Wang,Qing Hu,Ximing Wang,Yanpeng Huang,Yuanhao Wang,Fenghuan Wang
Methane reforming with carbon dioxide (DRM) is one promising way to achieve carbon neutrality and convert methane to syngas for high-value chemical production. Catalyst development with better performance is the key to its potential large-scale industrial application due to its deactivation caused by carbon deposition and metal sintering. Hence, a Ni/CeO2catalyst (Ni/CeO2-M) with higher CO2conversion and better stability is prepared, supported on CeO2precipitated via a novel microimpinging stream reactor. A series of ex-situ or in-situ characterizations, such as CO titration measurements, two-step transient surface reaction (two-step TSR), CO2and CH4temperature-programmed surface reaction (CO2-TPSR and CH4-TPSR), X-ray absorption fine structure (XAFS), and in-situ Raman spectroscopy study, were used to investigate its structure and mechanism. In contrast to Ni supported on commercial CeO2(Ni/CeO2-C), the Ni/CeO2-M catalyst with stronger lattice oxygen mobility and higher oxygen storage capacity enhances its CO2activation ability and carbon deposition. The Ni particle size of the Ni/CeO2-M catalyst decreased, and a higher oxidation state was obtained due to the strong metal–support interaction. Besides the reaction performance improvement of the Ni/CeO2-M catalyst, the novel microimpinging stream reactor could achieve catalyst continuous production with a high preparation efficiency. This work provides a novel method for the high-performance catalyst preparation for DRM reaction and its mechanism study gives a deep insight into high-performance catalyst development via bottom-up study.Keywords:dry reforming of methane;oxygen vacancy;Ni/CeO2catalyst
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
ChemCatChem
·
2022
·Vol. 14
·期 21
·e202200762
·
IF 5.497
Mingyue Liao,Yingying Chen,Minmin Chen,Kang Hui Lim,Ziwei Li,Hong Wu,Xiong He,Qiao Zhou,Sibudjing Kawi
Graphical Reforming of methane : A series of CeO 2 nanorod@Ni phyllosilicate (CeO 2 @NiPhy) catalysts with good sintering resistance of both Ni and CeO 2 were designed for CO 2 reforming of methane (DRM) reaction. With the NiPhy shell thickness of 9 nm, CeO 2 @NiPhy-9 shows stable performance for DRM. In-situ diffuse reflectance infrared Fourier transform spectra result demonstrates that DRM reaction takes place with a bi-functional mechanism on CeO 2 @NiPhy. Preventing the sintering of nano-catalyst is crucial to maintain their performance especially for high-temperature reactions such as CO 2 reforming of methane (DRM) reaction. In this paper, we design CeO 2 nanorod@Ni phyllosilicate (CeO 2 @NiPhy) catalysts with different NiPhy shell thickness to simultaneously preserve the morphology of CeO 2 nanorod and prevent the sintering of Ni. Compared with Ni/CeO 2 supported catalyst, CeO 2 @NiPhy core-shell catalyst with a shell thickness of 9 nm exhibits much better performance for DRM with stable CH 4 and CO 2 conversions of 75 % and 80 % respectively and lower carbon deposition due to high Ni sintering resistance and higher thermal stability of CeO 2 during calcination and DRM reaction thereby higher oxygen vacancies concentration. In-situ diffuse reflectance infrared Fourier transform spectra result demonstrates that DRM reaction takes place with a bi-functional mechanism on CeO 2 @NiPhy. This design strategy can be applied to prepare other nano-catalysts with high sintering resistance of both active metal and catalyst support for high-temperature applications.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2019
·
IF 0
Xiao Fang Chen,Ning Jiang,Song Hu,Li Mo He,Guang Liao,Qiang Qiang Ren,Sheng Su,Yi Wang,Jun Xiang,Ji Hua Qiu
The conditions (adsorption duration and pH) for removal of nickel ions from nickel electroplating wastewater by adsorbing on activated carbon were studied. Ni/AC catalysts prepared by adsorption under alkaline conditions with high removal rate of Ni(II) has been chosen for catalytic steam reforming of toluene, and its catalytic performances were evaluated compared to that of Ni/AC catalysts prepared by impregnation. Alkaline conditions facilitated the removal of Ni(II) from nickel electroplating wastewater by AC and pH=9 in especial, was a critical point above which Ni(II) could be removed efficiently. The removal rate within 20 min reached up to more than 97%. After H2 reduction, the catalytic activity of Ni/AC-Ad was observed in catalytic steam reforming of toluene and then gradually decreased with the reaction time. Both the toluene conversion and hydrogen production with Ni/AC-Ad were about 65% of those with Ni/AC-Im at similar Ni loading rate. Under alkaline conditions, most of the nickel adsorbed on AC was Ni(OH)2 complex. This adsorption state led to a larger average size of nickel particle in Ni/AC-Ad than that in Ni/AC-Im. The uneven size of nickel particles on the surface caused poor dispersion of active spots, agglomeration and sintering, resulting in gradual deactivation of Ni/AC-Ad prepared under alkaline conditions during catalytic steam reforming of toluene.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
FUEL
·
2019
·
IF 5.128
Limo He,Guang Liao,Song Hu,Long Jiang,Hengda Han,Hanjian Li,Qiangqiang Ren,Mohamed E. Mostafa,Xun Hu,Yi Wang,Sheng Su,Jun Xiang
The effects of reaction temperature (range from 500 °C to 800 °C) on multiple competitive processes were studied for the co-production of hydrogen and carbon nanotubes (CNTs) during catalytic reforming of toluene over Ni/α-Al 2 O 3 . With the temperature raising from 500 to 800 °C, H 2 yield increased by 7 times while H 2 proportion slightly decreased 5 vol% due to the competitive effect between steam reforming and reverse water–gas shift (WGS) reaction. Coke amounts (including amorphous carbon and CNTs) firstly increased and then decreased, which was determined by the competitive rate of formation and consumption reaction. Detailed characterization indicated the yield and quality of CNTs improved with the temperature increasing from 500 to 650 °C and reached the maximum at 650 °C, resulting from the enhancing transformation from amorphous to CNTs and consumption of amorphous carbon by steam. However, the growth of CNTs was suppressed by further increasing temperature, and almost no CNTs were generated at 800 °C. The higher temperature aggravated the sintering of Ni and enlarged their particle size, which was not conduced to CNTs growth.
研究领域:
化学工程
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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
·
IF 8.328
Yane Zheng,Kongzhai Li,Hua Wang,Dong Tian,Yuhao Wang,Xing Zhu,Yonggang Wei,Min Zheng,Yongming Luo
Chemical-looping reforming of methane (CLRM) offers an effective approach for coproducing syngas and pure hydrogen. In this work, CeO 2 nano particles (2–3 nm) are well dispersed on the wall surface of three-dimensional ordered macroporous (3DOM) LaFeO 3 , obtaining a highly efficient oxygen carrier for the CLRM technology. The physical and chemical properties of the oxygen carriers were characterized by SEM, TEM, H 2 -TPR, XPS, XRD, CH 4 -TPR and CH 4 -TPD techniques. It is found that the presence of CeO 2 on LaFeO 3 results in the formation of Ce 3+ and Fe 2+ due to the CeO 2 -LaFeO 3 interaction. The coexistence of Ce 3+ and Fe 2+ irons induces abundant oxygen vacancies on the mixed oxides, which strongly improves the reducibility, oxygen mobility and reactivity for methane oxidation. The presence of CeO 2 also improves the resistance towards carbon deposition formation, and this allows the CeO 2 /LaFeO 3 materials own high available oxygen storage capacity (available OSC, the maximum amount of oxygen consumed by methane reduction without the formation of carbon deposition). It is also noted that the agglomeration of CeO 2 nano particles would reduce the reactivity of oxygen carriers. Among all the obtained samples, the 10% CeO 2 /LaFeO 3 sample exhibits the highest yields of syngas (9.94 mmol g −1 ) and pure hydrogen (3.38 mmol g −1 ) without the formation of carbon deposition, which are much higher than that over the pure LaFeO 3 sample (5.73 mmol g −1 for syngas yield and 2.00 mmol g −1 for hydrogen yield). In addition, the CeO 2 /LaFeO 3 oxygen carrier also showed high stability during the successive CLRM testing either in the activity (yields of syngas and pure hydrogen) or structure (macroporous frameworks) aspect.
研究领域:
能源科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2016
·
IF 3.652
Zhen-Yi Du,Xia Wang,Zhi-Hua Zhang,Jie Feng,Yu-Hong Qin,Bin-Bin Zhang,Wen-Ying Li
The reforming characteristics of biomass volatiles on anthracite chars were investigated by comparing the structural evolution of tars derived from cellulose and lignin as the major biomass components. In a two-stage quartz reactor, the pyrolysis volatiles of cellulose and lignin were produced in the first stage and then reformed in the second stage with or without the presence of anthracite chars between 600 and 900 °C. The results show that the presence of anthracite chars enhanced the destruction of volatiles of both feedstocks. Furthermore, the tar yields of lignin showed a slower decreasing trend with temperature than those of cellulose, suggesting that the lignin volatiles were more refractory to be reformed. The lignin tars had higher molecular weights and contained higher percentage of compounds with large aromatic ring systems (≥3 fused benzene rings) than cellulose tars in the studied temperature range. Compositional analysis revealed that tars of both feedstocks experienced the transition from phenolic compounds to polycyclic aromatic hydrocarbons with increasing temperature. The surface areas of anthracite chars were reduced because of coke deposition after interacting with the volatiles of both feedstocks below 800 °C, above which the net gasification of chars took place.
研究领域:
能源科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2022
·
IF 8.634
Yuchen Jiang,Xianglin Li,Chao Li,Lijun Zhang,Shu Zhang,Bin Li,Shuang Wang,Xun Hu
Pyrolysis is a thermochemical route for converting waste plastics into hydrocarbons that might be further upgraded to fine chemicals via the process such as hydrotreatment. In this study, the pyrolysis of five typical plastics (PE, PP, PVC, PS and PET) and steam reforming of their derived volatiles were coupled in one process, named as pyro-reforming. The reaction behaviors, especially the property of their derived cokes, in the pyro-reforming were investigated. The results indicated that the volatiles from the pyrolysis of PE had the highest reactivity with steam to produce H 2 of the highest yield, followed by that of PP, PVC, PET and PS. The Cl in PVC promoted nickel sintering, enhanced formation of heavy aromatics through aromatization. Moreover, the existence of Cl interrupted formation of carbon nanotube, forming the highest amount of coke with hemp rope-like fiber form of very coarse surface. This was very different from the carbon nanotube form of coke with smooth surface and uniform outer/inner diameters from the pyro-reforming of PE or PP. The pyro-reforming of PET or PS generated mainly the aromatic intermediates that were chemically more inert in steam reforming, forming polymeric type of coke with no carbon nanotube morphology and very low crystallinity .
研究领域:
能源科学
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化学工程
✓ 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）