Catalytic Decomposition of Ethanol over Bimetallic Nico Catalysts for Carbon Nanotube Synthesis

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0039 ◽

2020 ◽

Author(s):

Anand Kumar ◽

Anchu Ashok

Keyword(s):

Active Sites ◽

Carbon Deposition ◽

Catalytic Decomposition ◽

Decomposition Reaction ◽

Coke Deposition ◽

Particle Analysis ◽

Multiwalled Carbon ◽

Ethanol Decomposition ◽

Co Nanoparticles ◽

Carbon Nanotube Synthesis

In this work we investigate the use of NiCo bimetal/oxide as catalyst for hydrogen production from ethanol, with a focus on the deactivation pattern and the nature of the observed carbon deposition. It is well known that sintering and coke deposition during decomposition reaction significantly reduces the activity of the catalysts at higher temperature, by blocking the active sites of the catalysts. During ethanol decomposition reaction, the cleavage of C-C bond produces adsorbed *CH4 and *CO species that further decompose to form carbonaceous compounds. FTIR in-situ analysis was conducted between 50 to 400°C for all the catalysts to understand the reaction mechanism and product selectivity. Cobalt was found to be selective for aldehyde and acetate, whereas bimetallic Ni-Co was selective for the formation of CO at 400°C along with aldehyde. Complete conversion of ethanol was observed at 350°C and 420°C for NiCo and Cobalt respectively indicating an improvement in the rate of conversion when Ni was added to cobalt. The crystallinity, morphology and particle analysis of the used catalyst after reaction were studied using XRD, SEM and TEM respectively. The XRD shows the complete phase change of porous NiCoO2 to NiCo alloy and SEM indicates the presence of fibrous structure on the surface with 91.7 % of carbon while keeping 1:1 ratio of Ni and Co after the reaction. The detailed analysis of carbon structure using HRTEM-STEM shows the simultaneous growth of carbon nano fibers (CNFs) and multiwalled carbon nanotubes (MWCNTs) that were favored on larger and smaller crystallites respectively. Analysis of carbon formation on individual Co catalyst and bimetallic NiCo catalyst shows a clear difference in the initiation pattern of carbon deposition. Metallic Co nanoparticles were found to be more mobile where Co disperses along the catalysts surface, whereas NiCo nanoparticles were relatively less mobile, and maintained their structure.

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

C – Journal of Carbon Research ◽

10.3390/c6020023 ◽

2020 ◽

Vol 6 (2) ◽

pp. 23

Author(s):

Randy Vander Wal ◽

Mpila Makiesse Nkiawete

Keyword(s):

Energy Storage ◽

Active Sites ◽

Fossil Fuel ◽

Carbon Materials ◽

Carbon Deposition ◽

Catalytic Decomposition ◽

Solid Carbon ◽

Thermocatalytic Decomposition ◽

Forms Of Carbon ◽

Decarbonization Process

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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Effect of Ni incorporation in cobalt oxide lattice on carbon formation during ethanol decomposition reaction

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2019.05.013 ◽

2019 ◽

Vol 254 ◽

pp. 300-311 ◽

Cited By ~ 7

Author(s):

Anchu Ashok ◽

Anand Kumar ◽

Janarthanan Ponraj ◽

Said A. Mansour ◽

Faris Tarlochan

Keyword(s):

Cobalt Oxide ◽

Decomposition Reaction ◽

Carbon Formation ◽

Ethanol Decomposition

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Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch-Leaf” Electrode for High-Energy Sodium–Sulfur Batteries

Nano-Micro Letters ◽

10.1007/s40820-020-00563-6 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Wenyan Du ◽

Kangqi Shen ◽

Yuruo Qi ◽

Wei Gao ◽

Mengli Tao ◽

...

Keyword(s):

Active Sites ◽

High Performance ◽

Electrochemical Reaction ◽

Molecular Layer ◽

Specific Capacity ◽

High Energy ◽

Reduction Reaction ◽

Biomimetic Design ◽

Co Nanoparticles ◽

Sodium Sulfur

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.

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Bio-DEE Synthesis and Dehydrogenation Coupling of Bio-Ethanol to Bio-Butanol over Multicomponent Mixed Metal Oxide Catalysts

Catalysts ◽

10.3390/catal11060660 ◽

2021 ◽

Vol 11 (6) ◽

pp. 660

Author(s):

Izabela S. Pieta ◽

Alicja Michalik ◽

Elka Kraleva ◽

Dusan Mrdenovic ◽

Alicja Sek ◽

...

Keyword(s):

Active Sites ◽

Internal Combustion Engines ◽

Mixed Oxides ◽

Catalyst Activity ◽

Product Distribution ◽

Coke Deposition ◽

Precipitation Method ◽

Mixed Metal Oxide ◽

Low Carbon ◽

Municipal Solid Wastes

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods from municipal solid wastes (MSWs) are sought for application as energy carriers or direct drop-in fuels/chemicals in the near-future low-carbon power generation systems and internal combustion engines. Among the studied energy vectors, C1-C2 alcohols and ethers are mainly addressed. This study presents a potential bio-derived ethanol oxidative coupling in the gas phase in multicomponent systems derived from hydrotalcite-containing precursors. The reaction of alcohol coupling to ethers has great importance due to their uses in different fields. The samples have been synthesized by the co-precipitation method via layered double hydroxide (LDH) material synthesis, with a controlled pH, where the M(II)/M(III) ≈ 0.35. The chemical composition and topology of the sample surface play essential roles in catalyst activity and product distribution. The multiple redox couples Ni2+/Ni3+, Cr2+/Cr3+, Mn2+/Mn3+, and the oxygen-vacant sites were considered as the main active sites. The introduction of Cr (Cr3+/Cr4+) and Mn (Mn3+/Mn4+) into the crystal lattice could enhance the number of oxygen vacancies and affect the acid/base properties of derived mixed oxides, which are considered as crucial parameters for process selectivity towards bio-DEE and bio-butanol, preventing long CH chain formation and coke deposition at the same time.

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Thermo-catalytic decomposition of polystyrene waste: Comparative analysis using different kinetic models

Waste Management & Research ◽

10.1177/0734242x19865339 ◽

2019 ◽

Vol 38 (2) ◽

pp. 202-212 ◽

Cited By ~ 14

Author(s):

Ghulam Ali ◽

Jan Nisar ◽

Munawar Iqbal ◽

Afzal Shah ◽

Mazhar Abbas ◽

...

Keyword(s):

Activation Energy ◽

Copper Oxide ◽

Solid Waste ◽

Thermodynamic Parameters ◽

Model Fitting ◽

Catalytic Decomposition ◽

Decomposition Reaction ◽

Inert Atmosphere ◽

Heating Rates ◽

Model Free

Due to a huge increase in polymer production, a tremendous increase in municipal solid waste is observed. Every year the existing landfills for disposal of waste polymers decrease and the effective recycling techniques for waste polymers are getting more and more important. In this work pyrolysis of waste polystyrene was performed in the presence of a laboratory synthesized copper oxide. The samples were pyrolyzed at different heating rates that is, 5°Cmin−1, 10°Cmin−1, 15°Cmin−1 and 20°Cmin−1 in a thermogravimetric analyzer in inert atmosphere using nitrogen. Thermogravimetric data were interpreted using various model fitting (Coats–Redfern) and model free methods (Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman). Thermodynamic parameters for the reaction were also determined. The activation energy calculated applying Coats–Redfern, Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman models were found in the ranges 105–148.48 kJmol−1, 99.41–140.52 kJmol−1, 103.67–149.15 kJmol−1 and 99.93–141.25 kJmol−1, respectively. The lowest activation energy for polystyrene degradation in the presence of copper oxide indicates the suitability of catalyst for the decomposition reaction to take place at lower temperature. Moreover, the obtained kinetics and thermodynamic parameters would be very helpful in determining the reaction mechanism of the solid waste in a real system.

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Production of COx-Free Hydrogen and Few-Layer Graphene Nanoplatelets by Catalytic Decomposition of Methane over Ni-Lignin-Derived Nanoparticles

Molecules ◽

10.3390/molecules27020503 ◽

2022 ◽

Vol 27 (2) ◽

pp. 503

Author(s):

Qiangu Yan ◽

Timothy Ketelboeter ◽

Zhiyong Cai

Keyword(s):

Active Sites ◽

Nickel Nanoparticles ◽

Catalytic Decomposition ◽

Graphene Nanoplatelets ◽

Methane Decomposition ◽

High Catalytic Activity ◽

Layer Graphene ◽

Free Hydrogen ◽

Decomposition Of Methane ◽

Few Layer Graphene

Nickel (Ni)-lignin nanocomposites were synthesized from nickel nitrate and kraft lignin then catalytically graphitized to few-layer graphene-encapsulated nickel nanoparticles (Ni@G). Ni@G nanoparticles were used for catalytic decomposition of methane (CDM) to produce COx-free hydrogen and graphene nanoplatelets. Ni@G showed high catalytic activity for methane decomposition at temperatures of 800 to 900 °C and exhibited long-term stability of 600 min time-on-stream (TOS) without apparent deactivation. The catalytic stability may be attributed to the nickel dispersion in the Ni@G sample. During the CDM reaction process, graphene shells over Ni@G nanoparticles were cracked and peeled off the nickel cores at high temperature. Both the exposed nickel nanoparticles and the cracked graphene shells may participate the CDM reaction, making Ni@G samples highly active for CDM reaction. The vacancy defects and edges in the cracked graphene shells serve as the active sites for methane decomposition. The edges are continuously regenerated by methane molecules through CDM reaction.

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High-Quality Multiwalled Carbon Nanotubes from Catalytic Decomposition of Carboneous Materials in Gas−Solid Fluidized Beds

Industrial & Engineering Chemistry Research ◽

10.1021/ie0711630 ◽

2008 ◽

Vol 47 (7) ◽

pp. 2166-2175 ◽

Cited By ~ 49

Author(s):

Seung Yong Son ◽

Yoong Lee ◽

Sungho Won ◽

Dong Hyun Lee ◽

Sang Done Kim ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Fluidized Beds ◽

Catalytic Decomposition ◽

High Quality ◽

Multiwalled Carbon

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Keggin-Type Heteropoly Salts as Bifunctional Catalysts in Aerobic Baeyer-Villiger Oxidation

Materials ◽

10.3390/ma11071208 ◽

2018 ◽

Vol 11 (7) ◽

pp. 1208 ◽

Cited By ~ 6

Author(s):

Katarzyna Pamin ◽

Jan Połtowicz ◽

Mateusz Prończuk ◽

Joanna Kryściak-Czerwenka ◽

Robert Karcz ◽

...

Keyword(s):

Oxidation Mechanism ◽

Decomposition Reaction ◽

Redox Properties ◽

Lewis Acidity ◽

Bifunctional Catalysts ◽

X Ray ◽

Ethanol Decomposition ◽

Iron Salts ◽

First Time ◽

Villiger Oxidation

The cobalt, manganese, and iron salts of tungstophosphoric or molybdophosphoric acid with growing content of metals were applied for the first time as catalysts in the Baeyer-Villiger (BV) oxidation of cyclohexanone to ε-caprolactone with molecular oxygen. The catalysts were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and ethanol decomposition reaction. Introduction of transition metals into the heteropoly structure increases the activity of resulting heteropoly salts in comparison with parent heteropolyacids. It was shown that the most active catalysts are salts of the heteropoly salts with one metal atom introduced and one proton left (HMPX) type, (where M = Co, Fe, Mn, and X = W, Mo) with the metal to proton ratio equal one. Among all of the studied catalysts, the highest catalytic activity was observed for HCoPW. The effect indicates that both the acidic and redox properties are required to achieve the best performance. The Baeyer-Villiger (BV) oxidation mechanism proposed identifies the participation of heteropoly compounds in three steps of the investigated reaction: oxidation of aldehyde to peracid (redox function), activation of carbonyl group (Lewis acidity), and decomposition of the Criegee adduct to ε-caprolactone (Brønsted acidity).

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Co nanoparticles combined with nitrogen-doped graphitic carbon anchored on carbon fibers as a self-standing air electrode for flexible zinc–air batteries

Journal of Materials Chemistry A ◽

10.1039/d0ta00793e ◽

2020 ◽

Vol 8 (15) ◽

pp. 7184-7191 ◽

Cited By ~ 3

Author(s):

Yangshen Chen ◽

Wenhui Zhang ◽

Zeyu Zhu ◽

Lulu Zhang ◽

Jiayi Yang ◽

...

Keyword(s):

Carbon Fibers ◽

Active Sites ◽

Graphitic Carbon ◽

Air Electrode ◽

Nitrogen Doped ◽

Co Nanoparticles ◽

Zinc Air Batteries

The flexible Co@NPCFs composites can provide rich active sites for electrocatalysis and are able to capture oxygen and desorb the OH− during the discharging and charging processes of ZABs.

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