H2 Production from Catalytic Methane Decomposition Using Fe/x-ZrO2 and Fe-Ni/(x-ZrO2) (x = 0, La2O3, WO3) Catalysts

An environmentally-benign way of producing hydrogen is methane decomposition. This study focused on methane decomposition using Fe and Fe-Ni catalysts, which were dispersed over different supports by the wet-impregnation method. We observed the effect of modifying ZrO2 with La2O3 and WO3 in terms of H2 yield and carbon deposits. The modification led to a higher H2 yield in all cases and WO3-modified support gave the highest yield of about 90% and was stable throughout the reaction period. The reaction conditions were at 1 atm, 800 °C, and 4000 mL(hgcat)−1 space velocity. Adding Ni to Fe/x-ZrO2 gave a higher H2 yield and stability for ZrO2 and La2O3 + ZrO2-supported catalysts whose prior performances and stabilities were very poor. Catalyst samples were analyzed by characterization techniques like X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed reduction (TPR), thermo-gravimetric analysis (TGA), and Raman spectroscopy. The phases of iron and the supports were identified using XRD while the BET revealed a significant decrease in the specific surface areas of fresh catalysts relative to supports. A progressive change in Fe’s oxidation state from Fe3+ to Fe0 was observed from the H2-TPR results. The carbon deposits on Fe/ZrO2 and Fe/La2O3 + ZrO2 are mainly amorphous, while Fe/WO3 + ZrO2 and Fe-Ni/x-ZrO2 are characterized by graphitic carbon.

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Influence of Nature Support on Methane and CO2 Conversion in a Dry Reforming Reaction over Nickel-Supported Catalysts

Materials ◽

10.3390/ma12111777 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1777 ◽

Cited By ~ 2

Author(s):

Anis Hamza Fakeeha ◽

Samsudeen Olajide Kasim ◽

Ahmed Aidid Ibrahim ◽

Ahmed Elhag Abasaeed ◽

Ahmed Sadeq Al-Fatesh

Keyword(s):

Supported Catalysts ◽

Space Velocity ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Impregnation Method ◽

X Ray Diffraction ◽

Wet Impregnation ◽

Surface Areas ◽

Diffraction Patterns ◽

Wet Impregnation Method

A promising method to reduce global warming has been methane reforming with CO2, as it combines two greenhouse gases to obtain useful products. In this study, Ni-supported catalysts were synthesized using the wet impregnation method to obtain 5%Ni/Al2O3(SA-5239), 5%Ni/Al2O3(SA-6175), 5%Ni/SiO2, 5%Ni/MCM41, and 5%Ni/SBA15. The catalysts were tested in dry reforming of methane at 700 °C, 1 atm, and a space velocity of 39,000 mL/gcat h, to study the interaction of Ni with the supports, and evaluation was based on CH4 and CO2 conversions. 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2 gave the highest conversion of CH4 (78 and 75%, respectively) and CO2 (84 and 82%, respectively). The catalysts were characterized by some techniques. Ni phases were identified by X-ray diffraction patterns. Brunauer–Emmett–Teller analysis showed different surface areas of the catalysts with the least being 4 m2/g and the highest 668 m2/g belonging to 5%Ni/Al2O3(SA-5239) and 5%Ni/SBA15, respectively. The reduction profiles revealed weak NiO-supports interaction for 5%Ni/Al2O3(SA-5239), 5%Ni/MCM41, and 5%Ni/SBA15; while strong interaction was observed in 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2. The 5%Ni/Al2O3(SA-6175) and 5%Ni/SiO2 were close with respect to performance; however, the former had a higher amount of carbon deposit, which is mostly graphitic, according to the conducted thermal analysis. Carbon deposits on 5%Ni/SiO2 were mainly atomic in nature.

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The Effect of Ni Addition onto a Cu-Based Ternary Support on the H2 Production over Glycerol Steam Reforming Reaction

Nanomaterials ◽

10.3390/nano8110931 ◽

2018 ◽

Vol 8 (11) ◽

pp. 931 ◽

Cited By ~ 15

Author(s):

Kyriaki Polychronopoulou ◽

Nikolaos Charisiou ◽

Kyriakos Papageridis ◽

Victor Sebastian ◽

Steven Hinder ◽

...

Keyword(s):

Sol Gel ◽

Strong Acid ◽

H2 Production ◽

Impregnation Method ◽

Reaction Products ◽

Cu Content ◽

Ni Addition ◽

Support Matrix ◽

Temperature Programmed ◽

H2 Yield

In the present study, Ni/Ce-Sm-xCu (x = 5, 7, 10 at.%) catalysts were prepared using microwave radiation coupled with sol-gel and followed by wetness impregnation method for the Ni incorporation. Highly dispersed nanocrystallites of CuO and NiO on the Ce-Sm-Cu support were found. Increase of Cu content seems to facilitate the reducibility of the catalyst according to the H2 temperature-programmed reduction (H2-TPR). All the catalysts had a variety of weak, medium and strong acid/basic sites that regulate the reaction products. All the catalysts had very high XC3H8O3 for the entire temperature (400–750 °C) range; from ≈84% at 400 °C to ≈94% at 750 °C. Ni/Ce-Sm-10Cu catalyst showed the lowest XC3H8O3-gas implying the Cu content has a detrimental effect on performance, especially between 450–650 °C. In terms of H2 selectivity (SH2) and H2 yield (YH2), both appeared to vary in the following order: Ni/Ce-Sm-10Cu > Ni/Ce-Sm-7Cu > Ni/Ce-Sm-5Cu, demonstrating the high impact of Cu content. Following stability tests, all the catalysts accumulated high amounts of carbon, following the order Ni/Ce-Sm-5Cu < Ni/Ce-Sm-7Cu < Ni/Ce-Sm-10Cu (52, 65 and 79 wt.%, respectively) based on the thermogravimetric analysis (TGA) studies. Raman studies showed that the incorporation of Cu in the support matrix controls the extent of carbon graphitization deposited during the reaction at hand.

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Effect of calcination temperature on properties of waste alkaline battery-based catalysts for deep oxidation of toluene and o-xylene

Energy & Environment ◽

10.1177/0958305x20932551 ◽

2020 ◽

pp. 0958305X2093255

Author(s):

Young-Kwon Park ◽

Min Ki Kim ◽

Sang Chul Jung ◽

Wang Geun Shim ◽

Seong Ho Jang ◽

...

Keyword(s):

Catalytic Activity ◽

Calcination Temperature ◽

Thermo Gravimetric Analysis ◽

Space Velocity ◽

Deep Oxidation ◽

Bet Surface Area ◽

Gravimetric Analysis ◽

Average Pore ◽

X Ray ◽

Alkaline Battery

To evaluate waste alkaline battery (WB) as a catalyst for deep oxidation of toluene and o-xylene, we investigated how calcination temperature influenced the catalytic activity of WB-based catalyst for catalyst preparation. Physicochemical properties of WB-based catalysts were characterized by BET (Brunauer Emmett Teller) analysis, XRD (X-ray diffraction), SEM/EDX (scanning electron microscope/energy dispersive X-ray), TGA/DTA (thermo gravimetric analysis/differential thermal analysis), and H2-TPR (hydrogen temperature programmed reduction). Major elements of WB-based catalysts were carbon, manganese, zinc, and iron. The catalytic activity of WB-based catalyst was significantly influenced by calcination temperatures ranging from 300 °C–600°C. An increase calcination temperature resulted in a significant decrease in the BET surface area and concentrations of surface carbon and chlorine of the WB-based catalyst, while levels of other components increased. The average pore diameter of the WB-based catalyst calcined at 400 °C (WB (400) catalyst) was the smallest. The concentrations of manganese and iron in WB (400) catalyst were the highest, while those of manganese and iron in the WB-based catalyst calcined at 300 °C (WB (300) catalyst) were the lowest. Therefore, a good performance of WB (400) catalyst was likely due to its higher concentrations of manganese and iron and smaller pore size. When GHSV (gas hourly space velocity) was 40,000 h−1, toluene and o-xylene were completely oxidized on WB (400) catalyst at 430 °C and 440 °C, respectively.

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Correlations Between Alkali and Crystallinity in lyocell-Based ACF Probed with X-Ray Diffraction

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2020.58.7.495 ◽

2020 ◽

Vol 58 (7) ◽

pp. 495-500

Author(s):

Young Min Jin ◽

Joon Hyuk Lee ◽

Sang Sun Choi

Keyword(s):

Thermo Gravimetric Analysis ◽

Thermal Characteristics ◽

Degree Of Crystallinity ◽

Bet Surface Area ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Surface Areas ◽

Potential Applications ◽

Activated Carbon Fibres

This study examined the effect of alkalis on lyocell-based activated carbon fibres (ACFs) with high Brunauer-Emmett-Teller (BET) surface areas, using X-ray diffraction (XRD). Here, alkali treatments were conducted using 10 ~ 25 % NaOH and KOH on lyocell samples for 3 h at ambient room temperature. A secondary treatment with 4 % each of KOH and H3PO4 for an additional 3 h followed. An activated form of the samples was prepared by oxidation (stabilisation), carbonisation, and activation. The final ACF form of the samples showed a porous structure with high BET surface areas (> 1,000 m<sup>2</sup> g<sup>-1</sup>). A 25 % dosage of NaOH produced the highest BET surface area compared to other samples. In terms of crystallinity, a 15 % dosage of KOH was found to be the optimum dosage to secure the highest degree of crystallinity among all samples. Meanwhile, the NaOH was successfully shifted the samples into the most distinct form of cellulose II. 15 % NaOH was found to secure the most stable thermal characteristics, as determined via thermo-gravimetric analysis. The present work demonstrates the various physio-chemistries of ACFs prepared with different proportions and types of alkalis, leading to intriguing potential applications.

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Highly efficient catalytic pyrolysis of polyethylene waste to derive fuel products by novel polyoxometalate/kaolin composites

Waste Management & Research ◽

10.1177/0734242x19899718 ◽

2020 ◽

Vol 38 (6) ◽

pp. 689-695

Author(s):

Saira Attique ◽

Madeeha Batool ◽

Mustansara Yaqub ◽

Oliver Goerke ◽

Duncan H. Gregory ◽

...

Keyword(s):

Catalytic Cracking ◽

Thermo Gravimetric Analysis ◽

Fuel Oil ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Gravimetric Analysis ◽

Impregnation Method ◽

X Ray ◽

Highly Efficient ◽

Cracking Catalysts

We report here alumina-substituted Keggin tungstoborate/kaolin clay composite materials (KAB/kaolin) as polyethylene cracking catalysts. KAB/kaolin composites with varying concentrations of KAB (10–50 wt.%) were synthesized by the wet impregnation method and successfully characterized by Fourier-transform infrared spectroscopy, powder X-ray diffraction, thermo-gravimetric analysis and scanning electron microscopy with energy dispersive X-ray spectroscopy analytical techniques. Use of KAB loaded kaolin composites as the catalyst for low-density polyethylene (LDPE) cracking exhibited a higher percentage of polymer conversion (99%), producing 84 wt.% of fuel oil and negligible amount (˂ 1 wt.%) of solid residue while thermal cracking produced ~22 wt.% residue. Furthermore, gas chromatography–mass spectrometry analysis of oil obtained by non-catalytic cracking exhibited a high selectivity to high molecular weight hydrocarbons (C13–C23) compared to the catalytic cracking where 70 mol.% of gasoline range hydrocarbons (C5–C12) were produced. We propose that higher cracking ability of our prepared catalysts might ensue from both Brønsted and Lewis acid sites (from KAB and kaolin respectively), which enhanced the yield of liquid fuel products and reduced the cracking temperature of LDPE. These findings suggest that the prepared composites were cost-effective and excellent cracking catalysts that could be recommended for highly efficient conversion of waste plastic materials to petrochemicals at an industrial scale.

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Evaluation of the Behavior of Hydrotalcite Like-Materials for CO2 Capture

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.830.3 ◽

2016 ◽

Vol 830 ◽

pp. 3-10 ◽

Cited By ~ 4

Author(s):

Dantiele W.S. Albuquerque ◽

Elisângela S. Costa ◽

Jussara L. de Miranda ◽

Rosana Drumond Gonçalves ◽

Luiza Cristina de Moura

Keyword(s):

Thermo Gravimetric Analysis ◽

Precipitation Method ◽

Maximum Efficiency ◽

Gravimetric Analysis ◽

Reduced Pressure ◽

Surface Areas ◽

Electrical Neutrality ◽

Different Temperatures ◽

Interlayer Region ◽

Co Precipitation

Several compounds are being investigated for CO2 capture, besides alkolamines, including solid materials as activated charcoal, zeolites, metal organic frameworks, metal oxides and hydrotalcites. Hydrotalcites, also called layered double hydroxides (LDHs), present some characteristics that are very interesting for CO2 capture, including their speed to achieve equilibrium and their high regeneration. These compounds can be represented by the general formula [M1-x2+Mx3+(OH)2]x+ [(An-)x/n.yH2O]x, where M2+ and M3+ are divalent metals and trivalent cations, respectively, and An- is an anion of valency n which occupies the interlayer region, and maintains electrical neutrality of these materials. In the present work, we have synthesized specific LDHs, thermally modified for CO2 sorption. LDH’s were synthesized intercalated with carbonate anions employing the heterogeneous precipitation method, also known as co precipitation method. After LDH's calcination at different temperatures, the formation of oxides was observed with different surface areas and therefore a varied adsorption capacity. The products were characterized by X-ray diffraction, infrared absorption spectroscopy and thermo gravimetric analysis. The maximum efficiency of CO2 adsorption was observed at reduced pressure with the calcined sample of LDH-CO3, Mg2Al which indicates that the material maintained stable and with a high crystallinity. These properties presented for LDH-CO3, Mg2Al synthesized in this work indicate that these materials can be good and also cheap candidates for CO2 capture.

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Catalytic Properties of Vanadium Nitride and the Effect of Preparative Parameters on its Microstructure

MRS Proceedings ◽

10.1557/proc-454-65 ◽

1996 ◽

Vol 454 ◽

Cited By ~ 1

Author(s):

Heock-Hoi Kwon ◽

Levi T. Thompson

Keyword(s):

Surface Area ◽

Catalytic Properties ◽

Space Velocity ◽

Reaction Rates ◽

Vanadium Nitride ◽

Gravimetric Analysis ◽

Vanadium Nitrides ◽

Surface Areas ◽

Pore Size Distributions ◽

Crystallite Sizes

AbstractIn this paper we describe the synthesis, morphologies, and catalytic properties of vanadium nitrides prepared via the temperature programmed reaction (TPR) of V2O5 (7 m2/gr) with ammonia. This reaction yielded VN with surface areas up to 60 m2/gr. Among the synthesis parameters, the molar hourly space velocity had the most significant influence on the BET surface areas, crystallite sizes, and pore size distributions. Thermal gravimetric analysis (TGA) and x-ray diffraction indicated that the solid state reaction of V2O5 with NH3 occurred as follows: V2O5 → V4O9 → VO2 → V2O3 → VO0.9 → V.N. Scanning electron microscopy revealed that the surface roughness increased as the transformation proceeded, which corresponds to the increase in surface area. The vanadium nitrides were exceptionally active for the dehydrogenation of butane with selectivities greater than 98 % to C4 olefins. The deactivation was very slow for these catalysts. The reaction rates increased with increasing surface area and were comparable to that of a commercial Pt-Sn/Al2O3 dehydrogenation catalyst.

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Synthesis of Smart Mesoporous Materials

MRS Proceedings ◽

10.1557/proc-775-p7.8 ◽

2003 ◽

Vol 775 ◽

Author(s):

G.V.Rama Rao ◽

Qiang Fu ◽

Linnea K. Ista ◽

Huifang Xu ◽

S. Balamurugan ◽

...

Keyword(s):

Mesoporous Silica ◽

Mesoporous Materials ◽

Fluorescent Dyes ◽

Thermo Gravimetric Analysis ◽

Molecular Transport ◽

Solute Diffusion ◽

Gravimetric Analysis ◽

Stimuli Responsive ◽

Porous Network ◽

Hybrid Mesoporous Materials

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.

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Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

Revista de Chimie ◽

10.37358/rc.08.7.1882 ◽

2008 ◽

Vol 59 (7) ◽

Author(s):

Madalina Angelusiu ◽

Maria Negoiu ◽

Stefania-Felicia Barbuceanu ◽

Tudor Rosu

Keyword(s):

Coordination Compounds ◽

Magnetic Moments ◽

Thermo Gravimetric Analysis ◽

Electronic Spectroscopy ◽

Transition Metal Ions ◽

Synthesis And Characterization ◽

Gravimetric Analysis ◽

Thermo Gravimetric ◽

New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

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Collagen And Carbon-Ferrous Nanoparticles Used As A Green Energy Composite Material For Energy Storage Devices

Current Materials Science ◽

10.2174/2666145413666201207202502 ◽

2020 ◽

Vol 13 ◽

Author(s):

Inbasekaran S. ◽

G. Thiyagarajan ◽

Ramesh C. Panda ◽

S. Sankar

Keyword(s):

Composite Material ◽

Thermo Gravimetric Analysis ◽

Value Added ◽

Green Energy ◽

Nano Particles ◽

Hydroxyl Group ◽

Gravimetric Analysis ◽

Circuit Testing ◽

Battery Cell ◽

Dc Voltage

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.

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