CO2 REFORMING OF METHANE OVER NI SUPPORTED ON MESOSTRUCTURED SILICA NANOPARTICLES (NI/MSN): EFFECT OF NI LOADING

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Siti Munirah Sidik ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Umi Aisah Asli
Keyword(s):  
Nickel Oxide ◽  
Silica Nanoparticles ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Mesostructured Silica ◽  
Physical Mixing ◽  
Mixing Method ◽  
Adsorption Desorption

A series of Ni incorporated Mesostructured Silica Nanoparticles (MSN) were prepared by physical mixing method. Electrolyzed nickel oxide was used as the Ni precursor. The N2 adsorption-desorption and X-Ray diffraction (XRD) analyses evidenced that the increase in Ni loading decreased the surface area and crystallinity, and increased Ni particle size in the catalyst, respectively. The activity of CO2 reforming of CH4 followed the order of 10Ni/MSN > 15Ni/MSN > 5Ni/MSN > MSN. The highest activity was achieved by 10Ni/MSN with the CH4 and CO2 conversion of 63.4% and 87.2 %, respectively. The results indicated that the presence of a suitable Ni amount in MSN was beneficial to achieve high catalytic activity due to its effect on the amount of active metal sites available for the reaction. Thus, the electrolyzed nickel oxide precursor and Ni/MSN catalyst prepared by electrochemical method and physical mixing synthesis has a potential to be utilized in CO2 reforming of CH4.

CO2 reforming of CH4 over Ni/mesostructured silica nanoparticles (Ni/MSN)

RSC Advances ◽  
2015 ◽  
Vol 5 (47) ◽  
pp. 37405-37414 ◽  
Author(s):  
S. M. Sidik ◽  
A. A. Jalil ◽  
S. Triwahyono ◽  
T. A. T. Abdullah ◽  
A. Ripin
Keyword(s):  
Silica Nanoparticles ◽  
Good Stability ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Mesostructured Silica

Higher basicity of Ni/MSN suppressed the formation of deactivated carbon and contributed to a good stability in CO2 reforming of CH4.

scholarly journals Activity Enhancement of P25 Titanium Dioxide by Zinc Oxide for Photocatalytic Phenol Degradation

2021 ◽  
Vol 16 (2) ◽  
pp. 310-319
Author(s):  
Yehezkiel Steven Kurniawan ◽  
Leny Yuliati
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Rate Constant ◽  
Phenol Degradation ◽  
Reaction Rate Constant ◽  
X Ray Diffraction ◽  
Physical Mixing ◽  
Mixing Method ◽  
Activity Enhancement

As a benchmark photocatalyst, P25 titanium dioxide (TiO2) nanomaterial has been widely reported for its remarkable photocatalytic activity under ultraviolet (UV) irradiation. However, approaches to further improve the photocatalytic activity of the P25 TiO2 are still required. In the present work, we reported the activity enhancement of the P25 TiO2 up to more than five times higher rate constant for phenol degradation when the P25 TiO2 was coupled with zinc oxide (ZnO). The composites were prepared by a physical mixing method of P25 TiO2 and ZnO with various weight ratios of 1:0.5, 1:1, and 1:2. The composite materials were then characterized using X-ray diffraction (XRD), diffuse-reflectance ultraviolet-visible (DR UV-vis), Fourier transform infrared (FTIR), and fluorescence spectroscopies. All the composites gave better activity than the P25 TiO2, in which the TiO2/ZnO 1:1 composite material exhibited the highest first-order reaction rate constant (0.43 h−1). This remarkable enhanced degradation rate was much higher than that of the unmodified TiO2 (0.08 h−1) and ZnO (0.13 h-1). The fluorescence study revealed that the electron-hole recombination on the P25 TiO2 could be suppressed by the ZnO, which would be the reason for such activity enhancement. A study on the effect of the scavenger showed that the hydroxyl radicals played a crucial role in the photocatalytic phenol degradation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Thermal Expansion Studies of Carbon Nanotube-Reinforced Silver Nanocomposite

2015 ◽  
Vol 70 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Dinesh Kumar ◽  
Sonia Nain ◽  
Ravi Kumar ◽  
Hemant Pal
Keyword(s):  
Thermal Expansion ◽  
Carbon Nanotube ◽  
Coefficient Of Thermal Expansion ◽  
X Ray Diffraction ◽  
Thermal Expansion Behaviour ◽  
Silver Composites ◽  
Physical Mixing ◽  
Silver Matrix ◽  
Mixing Method ◽  
Expansion Behaviour

AbstractIn the present study, a simple and highly effective physical mixing method was used to synthesise carbon nanotube (CNT)-reinforced silver nanocomposites. Composites were prepared with different contents (vol%) of functionalised multiwall nanotubes. The microstructure of synthesised nanocomposites was analysed by X-ray diffraction, electron diffraction spectroscopy, and scanning electron microscopy. Microstructural characterisations revealed good distribution of nanotubes in the silver matrix. The thermal expansion behaviour of the composites was studied in reference to the variation in nanotube volume content in the silver matrix. It was observed that the coefficient of thermal expansion decreased with the increase in the percentage of CNT volume. The thermal expansion of the CNT-reinforced silver composites decreased to 55 % of pure silver upon the introduction of 6 vol% of nanotubes into the silver matrix. The thermal expansion behaviour of the CNT-reinforced silver composites was also analysed theoretically using the rule of mixture and Schapery’s model. The CNT-reinforced silver composites may be a promising contact and thermal management material in electronic devices.

scholarly journals Mixing and Quantifying Multi-Component Materials for Pyrotechnic Applications

2014 ◽  
Vol 70 (a1) ◽  
pp. C1233-C1233
Author(s):  
Lisa Blair ◽  
Simon Coles ◽  
Ian Sinclair ◽  
Ranko Vrcelj
Keyword(s):  
Energetic Materials ◽  
Crystalline Lattice ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Macroscopic Structure ◽  
Metal Organic ◽  
Physical Mixing ◽  
Mixing Method ◽  
Distribution Of Components

This multidisciplinary research is looking at the relationship between components of a pyrotechnic product and how manufacturing, in particular the mixing method employed, affects its macroscopic structure and properties. For pyrotechnics to produce the desired effect the ingredients must be intimately mixed, however, the present physical mixing approach can lead to inconsistencies in performance between batches. X-ray computed tomography (CT) was used to investigate the distribution of components in a pyrotechnic mixture. Near-neighbour distances between particles were calculated and used to assess the homogeneity of the mixtures and the efficiency of combustion. Another strand of this research to overcome batch inconsistencies was by chemically binding pyrotechnic ingredients rather than physically mixing them together. One method of achieving this was through incorporating two or more components within the same crystalline lattice. This may be achieved through co-crystallisation or coordination in functional frameworks, thereby reducing the number of components in a physical mixture and minimising the variation between batches. Pang et al. have investigated using MOFs (metal-organic frameworks) to stabilise energetic materials [1]. The research presented here uses MOFs to bring together fuels and oxidisers into one framework to create a MOFirework. Numerous linkers and metal centres were investigated to build up a structural family to correlate structure with pyrotechnic function (e.g. changing burn colour; Sr = red, Ba = green). Both powder and single crystal X-ray diffraction were used to characterise the products. Differential scanning calorimetry was used to look at the thermal profiles to investigate their possible uses as pyrotechnics. Lastly, a burn test was carried out to determine their pyrotechnic effect (e.g. gas, smoke, gas, light, heat, colour, and sound) and quantitatively link this to structure.

scholarly journals Effect of NH3 Alkalization and MgO Promotion on the Performance of Ni/SBA-15 Catalyst in Combined Steam and Carbon Dioxide Reforming of Methane

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Phan H. Phuong ◽  
Luu C. Loc ◽  
Nguyen Tri ◽  
Nguyen P. Anh ◽  
Ha C. Anh
Keyword(s):  
Catalytic Performance ◽  
Ammonia Solution ◽  
Side Reactions ◽  
Co2 Conversion ◽  
X Ray Diffraction ◽  
Co2 Reforming ◽  
Isothermal Adsorption ◽  
X Ray ◽  
Co2 Reforming Of Ch4 ◽  
Mg Content

In this work, 31.4 wt.% Ni/SBA-15 (Ni/SBA-15) nonpromoted and alkalized with ammonia solution and by MgO promoter catalysts were prepared and used for combined steam and CO2 reforming of CH4 (bireforming). Effect of concentration of ammonia solution (NH3(aq)) (10–25 vol.%) and Mg content (3–12 wt.%) on the properties of the Ni/SBA-15 catalysts was investigated by low-angle and powder X-ray diffraction (XRD), N2-BET isothermal adsorption, SEM, TEM, EDS mapping, H2-TPR, and CO2-TPD methods. The performance of the catalysts in bireforming was assessed in the temperature range of 550–800°C. The enhancement of dispersion of NiO particles, reducibility, and basicity of alkalized Ni/SBA-15 catalysts were responsible for improving the catalytic performance of this catalyst. The results revealed that the Ni/SBA-15 treated with 15-25% NH3(aq) solution and promoted with 3-9% Mg exhibited high activity for CH4 conversion. Meanwhile, Ni6Mg/SBA-15 showed the highest CO2 conversion. Among tested catalysts, Ni/SBA-15-20NH3 and Ni9Mg/SBA-15 samples had an almost equal activity with a CH4 conversion of nearly 97% and a CO2 conversion of about 84% at 700°C thanks to its moderate affinity with both CO2 and CH4. However, the H2/CO ratio of the product mixture remained at 2.02 on the Ni/SBA-15-20NH3 catalyst and almost 1 on the Ni9Mg/SBA-15 sample. These results might be related to the fact that the alkalization of the Ni/SBA-15 catalyst by NH3(aq) solution had an advantage over using MgO because side reactions were unlikely to occur.

scholarly journals CO2 reforming of CH4 over M(Ca, Ba, Sr)xLa1-xNiO3 perovskites used as coke resistant catalyst precursor

2020 ◽  
pp. 40-40
Author(s):  
Ana Carolina Trevisani Souza ◽  
Marcelo da Silva Batista
Keyword(s):  
Catalytic Performance ◽  
Partial Substitution ◽  
High Catalytic Activity ◽  
Catalyst Precursor ◽  
Co2 Reforming ◽  
Temperature Programmed Oxidation ◽  
Co2 Reforming Of Ch4 ◽  
Co2 Reforming Of Methane ◽  
Temperature Programmed ◽  
Carbon Dioxide Co2

Methane (CH4) and carbon dioxide (CO2) are greenhouse gases that have been converted into synthesis gas for the production of oxygenated chemicals and hydrocarbons. In this paper, M(Ca, Ba, Sr)xLa1-xNiO3 (x=0.0, 0.3 and 0.5) doped perovskites were successfully synthesized as catalyst precursors aiming at high catalytic activity and stability in the CO2 reforming of methane. These perovskites were characterized by X-ray diffraction (XRD), temperature programmed reduction by H2 (H2-TPR) and O2-temperature programmed oxidation (TPO). Its activity and carbon suppression were investigated in the CO2 reforming of methane. Results showed formation of perovskite structure, but La2NiO4 spinel and NiO were also detected in doped perovskites. The Ca, Ba and Sr partial substitution has evident influence on the reduction behavior of perovskites. All the doped perovskites used as catalyst precursors had better catalytic performance than LaNiO3. However, increasing the doping content decreased activity. Among doped perovskites, Ca0.3La0.7NiO3 showed better catalytic performance for the methane reforming reaction.

scholarly journals Structural, Conductivity, and Dielectric Properties of Nickel Oxide and Copper (Cu) or Chromium (Cr) Doped Nickel Oxide Nanoparticles

2021 ◽  
Author(s):  
Ali Bashal ◽  
Tarob A Abdel Baset ◽  
Mostafa Abboudi ◽  
Hamza Qasem ◽  
Fahd Al-Wadaani
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Nickel Oxide ◽  
Spherical Particles ◽  
Relative Pressure ◽  
X Ray Diffraction ◽  
Nickel Oxide Nanoparticles ◽  
X Ray ◽  
Nio Nps ◽  
Adsorption Desorption

Abstract In this study, NiO NPs and doped NiO NPs were prepared in a two-step process and they were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption desorption. X-ray diffraction outcome clarified that all the patterns present the similar peaks that are attributed to the cubic variety of the NiO and all doping metals could be inserted into the NiO structure. TEM result showed that the NiO NPs are assembled side by side and aligned along the same direction to form small array shaped nano-agglomerates of 500 nm in length and 50–70 nm in diameter. Adsorption-desorption isotherms for N2 showed that NiO NPs represents type IV isotherms containing a hysteresis loop at relative pressure between 0.5 and 1.0. Hysteresis loop’s shape was of H2 type which is characteristic of inckbottle shaped pores. It was also in the shape of solids composed by small spherical particles. The dielectric properties and electrical conductivity for these samples were also studied within the temperature range 25oC – 110oC and within the frequency range 100 Hz to 0.3 MHz.

CO2 Reforming of CH4 on Mesoporous Alumina-Supported Cobalt Catalyst: Optimization of Lanthana Promoter Loading

2021 ◽  
Author(s):  
Ngoc Thang Tran ◽  
P. Senthil Kumar ◽  
Quyet Van Le ◽  
Nguyen Van Cuong ◽  
Pham T. T. Phuong ◽  
...  
Keyword(s):  
Cobalt Catalyst ◽  
Mesoporous Alumina ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4
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