scholarly journals The Effects of Ce and W Promoters on the Performance of Alumina-Supported Nickel Catalysts in CO2 Methanation Reaction

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Wojciech Gac ◽  
Witold Zawadzki ◽  
Magdalena Greluk ◽  
Grzegorz Słowik ◽  
Marek Rotko ◽  
...  
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Active Surface ◽  
Nickel Catalysts ◽  
Catalyst Characterization ◽  
Active Surface Area ◽  
Impregnation Method ◽  
Co2 Methanation ◽  
Methanation Reaction ◽  
Supported Nickel Catalysts

The influence of Ce and W promoters on the performance of alumina-supported nickel catalysts in the CO2 methanation reaction was investigated. The catalysts were obtained by the co-impregnation method. Nitrogen low-temperature adsorption, temperature-programmed reduction, hydrogen desorption, transmission electron microscopy, X-ray diffraction, and photoelectron spectroscopy studies were used for catalyst characterization. An introduction of Ce and W promoters (1–5 wt %) led to the decrease in mean Ni crystallite size. Gradual increase in the active surface area was observed only for Ce-promoted catalysts. The increase in CO2 conversion in methanation reaction at low-reaction temperatures carried out over Ce-promoted catalysts was attributed to the increase in the active surface area and changes in the redox properties. The introduction of small amounts of tungsten led to an increase in the activity of catalysts, although a decrease in the active surface area was observed. Quasi in situ XPS studies revealed changes in the oxidation state of tungsten under CO2 methanation reaction conditions, indicating the participation of redox promoter changes in the course of surface reactions, leading to an improvement in the activity of the catalyst.

scholarly journals The state of BEA zeolite supported nickel catalysts in CO2 methanation reaction

2021 ◽  
pp. 150421
Author(s):  
Wojciech Gac ◽  
Witold Zawadzki ◽  
Grzegorz Słowik ◽  
Marcin Kuśmierz ◽  
Stanislaw Dzwigaj
Keyword(s):  
Nickel Catalysts ◽  
The State ◽  
Co2 Methanation ◽  
Methanation Reaction ◽  
Bea Zeolite ◽  
Supported Nickel Catalysts

Flowerlike submicrometer gold particles: Size- and surface roughness-controlled synthesis and electrochemical characterization

2010 ◽  
Vol 25 (9) ◽  
pp. 1755-1760 ◽  
Author(s):  
Changsheng Shan ◽  
Dongxue Han ◽  
Jiangfeng Song ◽  
Ari Ivaska ◽  
Li Niu
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Electrocatalytic Activity ◽  
Active Surface ◽  
Molar Ratio ◽  
Active Surface Area ◽  
Step Method ◽  
Gold Particles ◽  
X Ray ◽  
One Step

Flowerlike submicrometer gold particles were synthesized through a simple one-step method using p-diaminobenzene as a reductant in the presence of poly(sodium 4-styrenesulfonate) in aqueous solution. The particle size with diameters ranging from 267 to 725 nm could be tuned by varying the molar ratio of poly(sodium 4-styrenesulfonate) to HAuCl4, which also resulted in tunable roughness. The gold particles were confirmed by scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. Cyclic voltammetry showed that the specific surface area of the flowerlike particles was larger than that of sphere particles. The obtained flowerlike particles with higher surface area also exhibited higher electrocatalytic activity toward H2O2 and O2. The increase of electrocatalytic activity could be attributed to the increase of the active surface area.

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

Increasing Active Surface Area to Fabricate Ultra-Hydrophobic Surface by Using “Black Silicon” with Bosch Etching Process

2012 ◽  
Vol 12 (6) ◽  
pp. 4919-4927 ◽  
Author(s):  
Nithi Atthi ◽  
Jakrapong Supadech ◽  
Gaetan Dupuy ◽  
On-uma Nimittrakoolchai ◽  
Apirak Pankiew ◽  
...  
Keyword(s):  
Surface Area ◽  
Hydrophobic Surface ◽  
Active Surface ◽  
Etching Process ◽  
Black Silicon ◽  
Active Surface Area

Facile deposition of Pt nanoparticles on Sb-doped SnO2 support with outstanding active surface area for the oxygen reduction reaction

2018 ◽  
Vol 8 (10) ◽  
pp. 2672-2685 ◽  
Author(s):  
Rhiyaad Mohamed ◽  
Tobias Binninger ◽  
Patricia J. Kooyman ◽  
Armin Hoell ◽  
Emiliana Fabbri ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Pt Nanoparticles ◽  
Active Surface ◽  
Reduction Reaction ◽  
Active Surface Area

Synthesis of Sb–SnO2 supported Pt nanoparticles with an outstanding ECSA for the oxygen reduction reaction.

scholarly journals Sensitive Electrochemical Detection of Caffeic Acid in Wine Based on Fluorine-Doped Graphene Oxide

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1604 ◽  
Author(s):  
Venkatesh Manikandan ◽  
Boopathi Sidhureddy ◽  
Antony Thiruppathi ◽  
Aicheng Chen
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Caffeic Acid ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Active Surface ◽  
Differential Pulse ◽  
Active Surface Area ◽  
Food And Beverage ◽  
Doped Graphene

We report here a novel electrochemical sensor developed using fluorine-doped graphene oxide (F-GO) for the detection of caffeic acid (CA). The synthesized graphene oxide (GO) and F-GO nanomaterials were systematically characterized with a scanning electron microscope (SEM), and the presence of semi-ionic bonds was confirmed in the F-GO using X-ray photoelectron spectroscopy. The electrochemical behaviours of bare glassy carbon electrode (GCE), F-GO/GCE, and GO/GCE toward the oxidation of CA were studied using cyclic voltammetry (CV), and the results obtained from the CV investigation revealed that F-GO/GCE exhibited the highest electrochemically active surface area and electrocatalytic activity in contrast to the other electrodes. Differential pulse voltammetry (DPV) was employed for the analytical quantitation of CA, and the F-GO/GCE produced a stable oxidation signal over the selected CA concentration range (0.5 to 100.0 μM) with a low limit of detection of 0.018 μM. Furthermore, the acquired results from the selectivity studies revealed a strong anti-interference capability of the F-GO/GCE in the presence of other hydroxycinnamic acids and ascorbic acid. Moreover, the F-GO/GCE offered a good sensitivity, long-term stability, and an excellent reproducibility. The practical application of the electrochemical F-GO sensor was verified using various brands of commercially available wine. The developed electrochemical sensor successfully displayed its ability to directly detect CA in wine samples without pretreatment, making it a promising candidate for food and beverage quality control.

Sign in / Sign up

Export Citation Format

Share Document