Variation in Catalytic Activity of Carbon Black during Methane Decomposition: Active Site Estimations from Surface Structural Characteristics

Kameya, Yuki; Hanamura, Katsunori

doi:10.1007/s10562-012-0794-4

Cited by 11 publications

(4 citation statements)

References 19 publications

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“…The conversion of methane with different types of carbon materials is expected to be similar in the late stages of the processes due to the formation of carbon deposits (coke) on the surface, which hinder the longevity of the carbon catalyst for hydrogen production . To the best of our knowledge, most of the current understanding of the effect of surface structure and doping on the CMD process is based on extrapolation of specific reaction steps’ findings ,, to the overall process and studies investigating the effect of heteroatomic doping toward the nonoxidative hydrogen production from methane on carbonaceous catalysts are lacking. , Therefore, it is mandatory that a thorough atomistic investigation of the CMD process, based on the carbonaceous catalyst structure modification, is performed in order to give insights about the main reaction mechanism, aiming at predicting intermediates’ and byproducts’ production at desired conditions, elucidating the main hydrogen formation channels and to guide the catalyst engineering.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Microkinetic Modeling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane

Xavier

Bauerfeldt

Sacchi

2023

ACS Appl. Mater. Interfaces

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The doping of graphitic and nanocarbon structures with nonmetal atoms allows for the tuning of surface electronic properties and the generation of new active sites, which can then be exploited for several catalytic applications. In this work, we investigate the direct conversion of methane into H2 and C2H x over Klein-type zigzag graphene edges doped with nitrogen, boron, phosphorus and silicon. We combine Density Functional Theory (DFT) and microkinetic modeling to systematically investigate the reaction network and determine the most efficient edge decoration. Among the four edge-decorated nanocarbons (EDNCs) investigated, N-EDNC presented an outstanding performance for H2 production at temperatures over 900 K, followed by P-EDNC, Si-EDNC and B-EDNC. The DFT and microkinetic analysis of the enhanced desorption rate of atomic hydrogen reveal the presence of an Eley–Rideal mechanism, in which P-EDNC showed higher activity for H2 production in this scenario. Coke deposition resistance in the temperature range between 900 and 1500 K was evaluated, and we compared the selectivity toward H2 and C2H4 production. The N-EDNC and P-EDNC active sites showed strong resistance to carbon poisoning, whereas Si-EDNC showed higher propensity to regenerate its active sites at temperatures over 1100 K. This work shows that decorated EDNCs are promising metal-free catalysts for methane conversion into H2 and short-length alkenes.

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Section: Introductionmentioning

confidence: 99%

First-Principles Microkinetic Modeling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane

Xavier

Bauerfeldt

Sacchi

2023

ACS Appl. Mater. Interfaces

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“…The CB used herein has a high specific surface of 68 m 2 ·g ¹1 , which is almost equal to that of CB used in prior reports. 17)19) The rate of H 2 production from CH 4 by using CB as a catalyst was measured by using a gas reaction system. A schematic of the gas reaction system is presented in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…The flow rate of CH 4 per sectional area of the reactor was 0.0051 sccm·mm ¹2 , which is about one hundredth of the flow rate per sectional area used in prior reports. 15), 17) The reactor was then heated to 5001100°C, and the reaction between CH 4 and CBs was started. The reacted gas was analyzed to identify the generated gases and evaluate the temperature-dependence of the gas generated via GC.…”

Section: Methodsmentioning

confidence: 99%

Methane decomposition for hydrogen production by catalytic activity of carbon black under low flow rate conditions

Tokunaga

Kishi

Yamakawa

et al. 2017

J. Ceram. Soc. Japan

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Recently, carbon materials were reported to work as catalysts for the production of H 2 from hydrocarbons. However, the hydrogen production rate is extremely low. To broaden the scope of carbon materials as catalysts for the decomposition of hydrocarbons, a higher H 2 production rate is required. Thus, the hydrogen production rate under conditions employing a low flow rate of hydrocarbon per unit area and a large quantity of carbon materials as the catalyst should be evaluated, and the influence of these conditions on the rate of H 2 production by carbon materials should be discussed. Herein, the H 2 production rate was measured under conditions employing a low flow rate of CH 4 and a large quantity of carbon black (CB) as a catalyst. H 2 production started at 600°C and the production rate was less than 0.1%. The transmission electron microscope image of CB heated in CH 4 atmosphere demonstrated that a low flow rate of CH 4 does not affect the reaction site (i.e., graphite edges) of CB. However, the H 2 production rate was extremely low compared to that achieved with a high flow rate. It is proposed that there is an optimal flow rate for maintaining the catalytic activity at the graphite edge of CB for decomposition of CH 4 .

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“…Four separate studies have shown low-resolution TEM of deposited carbon on carbon blacks [47,[66][67][68]. Results diverge, showing either uniformity of deposition or non-uniformity, though results in both cases are difficult to gauge given varied reactor bed configurations.…”

Section: Electron Microscopy In Tcdmentioning

confidence: 99%

Carbons as Catalysts in Thermo-Catalytic Hydrocarbon Decomposition: A Review

Wal

Nkiawete

2020

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Thermo-catalytic decomposition is well-suited for the generation of hydrogen from natural gas. In a decarbonization process for fossil fuel—pre-combustion—solid carbon is produced, with potential commercial uses including energy storage. Metal catalysts have the disadvantages of coking and deactivation, whereas carbon materials as catalysts offer resistance to deactivation and poisoning. Many forms of carbon have been tested with varied characterization techniques providing insights into the catalyzed carbon deposition. The breadth of studies testing carbon materials motivated this review. Thermocatalytic decomposition (TCD) rates and active duration vary widely across carbons tested. Regeneration remains rarely investigated but does appear necessary in a cyclic TCD–partial oxidation sequence. Presently, studies making fundamental connections between active sites and deposit nanostructures are few.

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Variation in Catalytic Activity of Carbon Black during Methane Decomposition: Active Site Estimations from Surface Structural Characteristics

Cited by 11 publications

References 19 publications

First-Principles Microkinetic Modeling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane

First-Principles Microkinetic Modeling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane

Methane decomposition for hydrogen production by catalytic activity of carbon black under low flow rate conditions

Carbons as Catalysts in Thermo-Catalytic Hydrocarbon Decomposition: A Review

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