INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
·
IF 7.139
Sulong Geng,Zhanguo Zhang,Junjie Li,Jianguo Qian,Jiao Liu,Jian Yu,Guangwen Xu
Catalyst samples for CH 4 decomposition were prepared from red mud (RM) by an acid-leaching neutralization precipitation approach. Water-washing the resultant precipitates multiple times, followed by drying at 105 °C and calcination at 500 °C, resulted in a threshold of residual Na 2 O, equivalent to 96% Na 2 O removal. Drying the precipitate at a higher temperature of 200 °C, followed by repeated water washing, provided a deeper Na 2 O removal of 99% and made the resultant samples more active for the targeted reaction. Subsequently, four catalyst samples with a simulated red mud composition and NaOH contents from 0 to 0.3 wt% were prepared and the catalytic test results revealed that the Na 2 O remaining in the RM-derived catalysts did not only inhibit their activation in CH 4 but also lower their maximal activities for CH 4 decomposition. Finally, two catalysts with the same simulated red mud composition and their Na impregnated respectively on Fe 2 O 3 and a mixture support of Al 2 O 3 -SiO 2 -TiO 2 were prepared and tested to explore the effect of Na distribution on the activation behavior of RM-derived catalysts for CH 4 decomposition. The activity testing results showed that it was the Na residual dispersed on iron oxides in the RM-derived samples to significantly inhibit the activation of CH 4 decomposition.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Yichi Zhang,Jingang Zhang,Dongping Sun,Jean-Marie Basset,Jingxia Qian,Lu Zhou
This study employed nonahydrate ferric nitrate and hexahydrate cobalt nitrate as precursors to fabricate catalysts via calcination, varying the iron-cobalt molar ratios (1: 5, 3: 4, 1: 1, 4: 3, 5: 1). It identified the optimal ratio for catalytic decomposition of methane (CDM) performance. Furthermore, adjusting the calcination temperature enabled control over the spinel content in catalysts with the optimal Fe: Co ratio (3: 4), resulting in a range of single and bimetallic catalysts with diverse spinel contents. Comparative analysis revealed the superior performance of bimetallic catalysts compared to single-metal counterparts. Specifically, under the conditions of 800 °C and GHSV 6 L/(g cat. ·h), Fe 3 Co 4 -700 °C achieved a maximum methane conversion of 75.6%, after maintaining a CDM test for 6 h, there is no decrease in stability. This is because the synergistic effect of Fe and Co bimetallic in the Fe 3 Co 4 -700 °C catalyst facilitates the transfer of charges between the bimetals, alters the surface charge density of the catalyst, enhances the electron donation capability of active sites, thereby favoring the adsorption and cracking processes of methane. XRD indicates that this catalyst with smaller crystallite size benefits the dispersion of catalytic active sites, thus improving the CDM performance. Results underscored the significant impacts of calcination temperature and metal ratio on the catalyst's spinel content and crystallite size. Characterization of spent catalysts unveiled carbon products primarily comprising carbon nano-onions, graphite, and carbon nanotubes, with the optimal catalyst yielding 5.8 g C /g cat. . Increasing calcination temperatures facilitated the formation of the spinel phase. At 150 °C, the Fe: Co (3: 4) catalyst had minimal spinel content, whereas at 300 °C, 700 °C, and 1000 °C, the contents are 9%, 11%, and 24%, respectively. Notably, at 1500 °C, the spinel content dramatically surged to 62%. The relationship between spinel content and spent catalyst crystallite size is not linear, the smaller crystal size is more conducive to the dispersion of catalytic active sites, thereby improving the CDM performance. Catalysts without spinel doping exhibited a crystallite size of around 32.2 nm, which decreased to 25.6 nm with 11% spinel content, and increased to 42.7 nm with 62% content. These findings yield profound insights into the influence of calcination temperature and iron cobalt ratios on catalyst performance, providing valuable guidance for the production of efficient CDM 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
Biomass Conversion and Biorefinery
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2022
·
IF 4.05
Zhao Rui,Xiao Na,Liu Yufei,Zhan Wei,Wu Zhengshun
In order to solve the pollution problem of agricultural waste and realize the harmlessness, reduction and resource of abandoned rice husk, silica was successfully extracted from rice husk by sol–gel method and used for methane decomposition to produce hydrogen. The effects of reaction temperature and mass fraction of sodium carbonate on the yield of silica were studied. When the reaction temperature was 120℃ and Na 2 CO 3 was 9 wt.%, the yield of silica was 52.3%. The effects of acid on the pyrolysis behavior of rice husk and the purity and the specific surface area of derived silica were investigated. The results showed that the thermal stability of rice husk and the purity of SiO 2 were improved after acid pretreatment. Compared with the silica sample prepared without acid pretreatment (4.7m 2 /g), the specific surface area of the silicon dioxide pretreated by HAc (SiO 2 -HAc) increased to 27m 2 /g. Rice husk-derived silica was used as a catalyst to produce hydrogen from methane decomposition, SiO 2 -HAc showed good catalytic activity, and the conversion of methane increased from 17.01% to 38.83%. This change was attributed to the formation of –Si‒C‒ species, which promoted the decomposition of methane. On this basis, Ni/SiO 2 -HCl and Ni/SiO 2 -HAc catalysts were prepared by loading metal Ni on the surface of rice husk-derived silica, and the conversion of methane increased to 74.33% and 60.73%, respectively.
研究领域:
环境科学
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材料科学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 8
·4893-4902
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IF 10.7
Zhao Sun,Yunhan Gong,Dongfang Cheng,Zhiqiang Sun
Catalytic methane decomposition shows the prominent superiority of generating hydrogen in one step with almost no carbon oxide production; however, it suffers from catalyst deactivation and low by-product carbon quality. Herein, a series of H2-reduced NixCr2Ox+3 (abbreviated as reduced NixCr2) catalysts were designed and synthesised for highly efficient methane decomposition and carbon nanotube production. A maximum methane conversion of 87.1% and hydrogen concentration of 91.8 vol% were achieved at 750 °C without deactivation. The results from XPS, XAS, and Raman reveal that the reduced NixCr2 catalysts have significant activity and stability. On the one hand, they form the Cr–O–Ni structure, thus possessing strong Ni–Cr2O3 interaction. On the other hand, the lattice oxygen of the reduced NixCr2 catalysts induces methane activation, thus accelerating methane activation, as demonstrated by the generation of a little amount of CO. In addition, the relationship between the types of carbon deposited and Ni/Cr ratio, decomposition temperature, and time was also revealed to guide carbon nanotube synthesis. Density functional theory calculation confirms the lowest dehydrogenation barrier of Ni(111)/Cr2O3(012), demonstrating the superiority of the Cr–O–Ni catalyzed methane decomposition. These findings provide innovative ideas for the construction of functionalized materials, which will substantially promote the development of methane decomposition.
研究领域:
材料科学
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化学工程
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催化技术
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 18
·14843-14856
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IF 3.201
Manoj Pudukudy,Zahira Yaakob,Qingming Jia,Mohd Sobri Takriff
The catalytic decomposition of methane is a strategic process to produce COx-free hydrogen and carbon nanomaterials. In this work, for the first time, highly porous ceria was prepared by a urea-assisted solid state combustion method and used as a support for the preparation of a set of platinum-promoted nickel catalysts. The amount of Pt varied from 0.05% to 0.2% while retaining 20% nickel in the catalysts. The prepared catalysts were completely characterized for their structural, textural and redox properties, and their catalytic performance was tested for undiluted methane decomposition. A fine surface dispersion of nickel oxide over ceria was observed in the prepared catalysts. No peaks related to Pt were observed in the catalysts, indicating its good surface dispersion. An enhancement was observed in the properties of the Ni/CeO2 catalyst after the addition of Pt as a promoter. The crystallinity of NiO was not altered by the addition of Pt, whereas the specific surface area of the catalysts was increased with the incremental addition of Pt. Furthermore, the reduction temperature of nickel oxide was shifted to low temperature in the Pt-promoted catalysts due to the hydrogen spillover effect. The surface composition and chemical states of the Pt-promoted Ni/CeO2 catalysts were further studied using XPS. The Pt-promoted Ni/CeO2 catalysts exhibited high catalytic efficiency for methane decomposition due to their improved catalytic properties. The addition of Pt increased the hydrogen yield, and a significant increase in the hydrogen yield was observed for the incremental amount of Pt in the catalysts. Moreover, by increasing the reaction temperature from 650 °C to 750 °C, the hydrogen yield increased significantly. A maximum hydrogen yield of 65% was observed for the 0.2% Pt@Ni/CeO2 catalyst at 750 °C. The enhanced activity and stability of the catalysts were attributed to the synergistic effects of Ni and Pt due to their fine surface dispersion over ceria with a proper metal–support interaction. Multiwalled carbon nanotubes with different diameters were deposited over the catalysts. The carbon nanotubes deposited over the Ni/CeO2 catalyst were found to be more homogeneous than the Pt-promoted catalysts. Moreover, a wide hollow channel was observed in the carbon nanotubes deposited over the Pt-promoted catalyst.
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
MATERIALS & DESIGN
·
2020
·
IF 6.289
Hu Sun,Guanghui Li,Jun Luo,Mingjun Rao,Zhiwei Peng,Tao Jiang
Existing nano-Mo 2 C preparation methods suffer from expensive raw materials, subtle operation demands and complex synthesis steps. Herein, both theoretical and experimental studies were performed to develop a more efficient and economical method for nano-Mo 2 C preparation. Reaction thermodynamics of gas-vapor system of CH 4 -MoO 3 -N 2 indicates that high-proportion inert gas significantly increases the required carbonization potential (CO/CO 2 ) for Mo 2 C formation, but surplus carbon produced from methane decomposition can trigger water gas producing reaction and Boudouard reaction to help meet the requirement. Nano-Mo 2 C was then synthesized by mixing N 2 -carried MoO 3 vapor with CH 4 under varying conditions including temperature, gas flowrate and vapor concentration. It is found that MoO 3 vapor experienced conversions to monoclinic MoO 2 to cubic Mo to hexagonal Mo 2 C, and all these stages could be finished in as short as about 6 s at 1100 °C with initial molar ratio of CH 4 to MoO 3 over 3.5. The final products were present as porous plate-like single crystals or chain-like polycrystals, which are determined by initial vapor concentration and gas flowrate. Furtherly, electrocatalytic properties of Mo 2 C nanocrystals for hydrogen evolution reaction were measured, and the sample with the largest specific surface area and cleaner surface showed competitive performance over reported nano-Mo 2 C.
研究领域:
材料科学
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化学工程
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能源科学
✓ 已验证
DOI
高影响因子
BIOMASS & BIOENERGY
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2025
·
IF 5.8
Haipeng Cui,Song Hu,Tao Yang,Limo He,Kai Xu,Long Jiang,Sheng Su,Yi Wang,Jun Xu,Jun Xiang
This study explores the fabrication of Fe–N co-doped biochar (Fe–NAC) from waste balsa wood as an efficient catalyst for methane decomposition and as a precursor to functional carbon materials. Ferric nitrate and urea were used as the respective sources of iron and nitrogen. The Fe-NAC catalyst achieved 85 % methane conversion within 200 min at 800 °C, a 3.4-fold improvement over the parent biochar (AC). The stable biochar structure anchors Fe 3 N nanoparticles, forming a hierarchical porous catalyst that enhances performance. Theoretical calculations revealed that the Fe-N structure alters the electron distribution, facilitating efficient electron transfer from Fe sites to methane and intermediates, demonstrating a synergistic effect of heteroatoms and carbon supports. Additionally, Fe-NAC exhibited exceptional microwave absorption properties, achieving a minimum reflection loss (RL) of −42.48 dB at 14.96 GHz with a 4.67 GHz effective absorption bandwidth (EAB). Adjusting the thickness enabled coverage of the entire 4–18 GHz spectrum. Radar cross-section (RCS) simulations demonstrated superior microwave attenuation across a wide range of angles, surpassing other biochars. This study introduces a novel Fe-N biochar synthesis method, highlights its catalytic performance in hydrogen production, and demonstrates its potential in electromagnetic wave absorption, providing insights for green energy and functional material development.
研究领域:
材料科学
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能源科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 22
·1831
·
IF 4.4
Dianfeng Cao,Yuwen Li,Chao Lv,Yongtao An,Jiangfeng Song,Mingcan Li,Xin Zhang
Catalytic methane decomposition (CMD) reaction is considered a promising process for converting greenhouse gas CH 4 into hydrogen and high-value-added carbon materials. In this work, a series of Al 2 O 3 -supported FeCo alloy catalysts were successfully prepared in the CMD process. Compared to the pre-reduced catalysts, the in situ reduced FeCo alloy catalysts showed higher methane conversion rates, with the highest reaching 83% at 700 °C, due to the finer active nanoparticle size and greater exposure of active site. Furthermore, the time-on-stream tests demonstrated that the catalytic activity of in situ reduced FeCo alloy catalysts could remain above 92.3% of the highest catalytic activity after 10 h. In addition, TEM analyses of the carbon products from the CMD in situ reduced catalysts revealed the production of carbon nanofibers and nanotubes several microns in length after the reaction. This indicates that the in situ reduced FeCo alloy catalysts more effectively promoted the growth of carbon nanofibers. These results could provide a viable strategy for future methane decomposition development aimed at producing hydrogen and high-value carbon.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Wenhan Zhao,Yingjie Li,Zhiwei Chu,Duo Xu,Kuihua Han,Zirui He
Catalytic methane decomposition (CMD) process has garnered significant attention for CO 2 -free hydrogen production. Fe catalyst has been widely investigated due to its low-cost and environmentally friendly features, but is prone to rapid deactivation due to elevated temperatures and coke deposition. To address these limitations, we synthesized a series of spinel-supported Fe catalysts with varying Fe/Mg/Al ratios via the sol–gel method. These catalysts were evaluated in a fixed-bed reactor, revealing that CMD performance depends significantly on Fe positioning within the spinel lattice in the as-prepared catalysts. Methane conversion was optimal and stable when Fe occupied octahedral sites, achieving 86.7 % CH 4 conversion and 92.9 % H 2 concentration in the outlet gas at 850 °C and 2 L g cat −1 h −1 . The mesoporous spinel structure enhances high-temperature stability and improves coke tolerance, which also contributed to additional layers of multi-walled carbon nanotubes. Density functional theory (DFT) calculations further identified the spinel-supported Fe catalysts as top performers. The energy barriers for the CMD process on Fe/MgAl 2 O 4 (1 1 1) and Fe/MgAl 2 O 4 (1 0 0) were lower than those on Fe(1 1 0). The difference charge density and Bader charge results of CH adsorption and dissociation on the structures, which was the rate-limiting step, demonstrated that the spinel support facilitated the efficient transportation and placement of electrons to the Fe cluster, thereby promoting C–H bond breaking. These findings offer novel insights into the design of cost-effective CMD catalysts with stable catalytic performance and high coke tolerance.
研究领域:
化学工程
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材料科学
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 25
·11783-11795
·
IF 4.682
Li Yuwen,Ding Fengyun,Zhou Linsen,Xiao Kela,Lv Chao,Li Peilong,Zhang Zexuan,Hu Cun,Shi Yan,Song Jiangfeng,Zhang Huaiqiang,Zhang Xin
Methane decomposition is an efficient pathway to obtain high-purity hydrogen and valuable carbon fibers, nanotubes, etc. In this work, a series of NiCo alloy catalysts with different Ni/Co ratios are successfully prepared using NiCoAl ternary layered double hydroxide (LDH) as precursors. By comparison with dual-LDH-derived catalysts and alumina-based catalysts, we found that the reduced catalysts from LDH have the characteristics of uniform particle size and distribution, and in subsequent the methane decomposition reaction over NiCo alloy catalysts show high catalytic activity and selectivity for carbon nanotubes. Furthermore, density functional theory (DFT) method is carried out to elucidate the catalytic decomposition mechanism of methane into hydrogen and carbon over a series of Ni n Co 4− n ( n = 0–4). These combined experimental and theoretical studies show that the introduction of Co element benefits the process of C–H dissociation. These combined experimental studies and DFT calculations can provide insights into the development of methane decomposition and other Ni-catalyzed methane reactions. Graphical abstract
研究领域:
材料科学
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催化化学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Li Yang,Chunmei Xin,Guohui Xuan,Shuai Liu,Fang Liu,Yanyan Ren
Catalytic methane decomposition is considered as a promising hydrogen production technology without CO 2 emission. Catalyst is generally required to reduce reaction temperature, among which, carbon-based catalysts are widely studied due to their excellent catalytic performance and low cost. Activated carbon (AC), although presents high initial activity, suffers from fast deactivation; In comparison, carbon black (CB) shows low activity but good stability, and its catalytic performance maintains ability inspires a novel method for AC optimization. According to the physical property difference of AC and CB, a novel catalyst is prepared by doping CB on the surface and in the pores of AC. And surface property modified by HNO 3 is also recommended, because the increase of functional groups further improves the adsorption performance. The results illustrate that AC N + BP2000-20:3 show advantages in hydrogen yield, weight increase velocity and carbon yield. Meanwhile, not only the initial activity is improved by a large margin, but also the deactivation time is progressively prolonged. The analysis results show that CB loading significantly increased the number of micropores, which is the key factor for the high initial catalytic activity. And the protrusion, induced by CB, are characterized by unique graphene edges defect, which provides active sites and furtherly promotes the reaction.
研究领域:
化学工程
·
材料科学
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）