scholarly journals Activated Carbon, Carbon Nanofibers and Carbon-Covered Alumina as Support for W2C in Stearic Acid Hydrodeoxygenation

2019 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Luana Souza Macedo ◽  
Victor Teixeira da Silva ◽  
Johannes Bitter
Keyword(s):  
Activated Carbon ◽  
Stearic Acid ◽  
Carbon Nanofibers ◽  
Carbon Materials ◽  
Catalyst Support ◽  
Carbon Support ◽  
Product Distribution ◽  
Mesopore Volume ◽  
Catalytic Activities ◽  
Carbon Covered Alumina

Carbon materials play a crucial role in sorbents and heterogeneous catalysis and are widely used as catalyst support for several reactions. This paper reports on an investigation of tungsten carbide (W2C) catalyst on three types of carbon support, namely activated carbon (AC), carbon nanofibers (CNF) and carbon-covered alumina (CCA). We evaluated their activity and selectivity in stearic acid hydrodeoxygenation at 350 °C and 30 bar H2. Although all three W2C catalysts displayed similar intrinsic catalytic activities, the support did influence product distribution. At low conversions (<5%), W2C/AC yielded the highest amount of oxygenates relative to W2C/CNF and W2C/CCA. This suggests that the conversion of oxygenates into hydrocarbons is more difficult over W2C/AC than over W2C/CNF and W2C/CCA, which we relate to the lower acidity and smaller pore size of W2C/AC. The support also had an influence on the C18-unsaturated/C18-saturated ratio. At conversions below 30%, W2C/CNF presented the highest C18-unsaturated/C18-saturated ratio in product distribution, which we attribute to the higher mesopore volume of CNF. However, at higher conversions (>50%), W2C/CCA presented the highest C18-unsaturated/C18-saturated ratio in product distribution, which appears to be linked to W2C/CCA having the highest ratio of acid/metallic sites.

scholarly journals Carbon nanomaterials for supercapacitors: two electrode scheme

2021 ◽  
Vol 340 ◽  
pp. 01035
Author(s):  
Maxim V. Popov ◽  
Alexander G. Bannov ◽  
Stepan I. Yusin
Keyword(s):  
Activated Carbon ◽  
Carbon Nanofibers ◽  
Carbon Nanomaterials ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Expanded Graphite ◽  
Thermally Expanded Graphite ◽  
Rice Hulls ◽  
Texture Characteristics ◽  
Electrodes For Supercapacitors

In this paper, the electrochemical and texture characteristics of electrode materials made of a number of promising carbon materials for supercapacitors were considered. Carbon nanofibers, thermally expanded graphite, and activated carbon derived from rice hulls were used as electrodes for supercapacitors. The paper presents a technique of synthesis of these electrode materials. A comparison of the capacitive characteristics of the electrodes using two-electrode scheme was carried out.

scholarly journals Activated carbon as catalyst support: precursors, preparation, modification and characterization

2020 ◽  
Vol 16 ◽  
pp. 1188-1202 ◽  
Author(s):  
Melanie Iwanow ◽  
Tobias Gärtner ◽  
Volker Sieber ◽  
Burkhard König
Keyword(s):  
Activated Carbon ◽  
Carbon Materials ◽  
Chemical Activation ◽  
Catalyst Support ◽  
Carbon Sources ◽  
Ultrasonic Spray Pyrolysis ◽  
Nitrogen Adsorption ◽  
Deep Eutectic Solvents ◽  
Preparation Methods ◽  
Dependent Modification

The preparation of activated carbon materials is discussed along selected examples of precursor materials, of available production and modification methods and possible characterization techniques. We evaluate the preparation methods for activated carbon materials with respect to its use as catalyst support and identify important parameters for metal loading. The considered carbon sources include coal, wood, agricultural wastes or biomass as well as ionic liquids, deep eutectic solvents or precursor solutions. The preparation of the activated carbon usually involves pre-treatment steps followed by physical or chemical activation and application dependent modification. In addition, highly porous materials can also be produced by salt templating or ultrasonic spray pyrolysis as well as by microwave irradiation. The resulting activated carbon materials are characterized by a variety of techniques such as SEM, FTIR, nitrogen adsorption, Boehm titrations, adsorption of phenol, methylene blue and iodine, TPD, CHNS/O elemental analysis, EDX, XPS, XRD and TGA.

Hierarchical porous nitrogen doping activated carbon with high performance for supercapacitor electrodes

RSC Advances ◽  
2016 ◽  
Vol 6 (19) ◽  
pp. 15320-15326 ◽  
Author(s):  
Juan Zeng ◽  
Qi Cao ◽  
Bo Jing ◽  
Xiuxiang Peng
Keyword(s):  
Activated Carbon ◽  
Carbon Nanofibers ◽  
High Performance ◽  
Nitrogen Doping ◽  
Carbon Materials ◽  
Chemical Activation ◽  
Hierarchical Porous ◽  
Composite Carbon ◽  
Subsequent Chemical

Hierarchical porous nitrogen doping activated carbon materials were designed and prepared by carbonization of electrospun composite carbon nanofibers and subsequent chemical activation.

scholarly journals Development of palladium catalysts modified by ruthenium and molybdenum as anode in direct ethanol fuel cell

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yonis Fornazier Filho ◽  
Ana Caroliny Carvalho da Cruz ◽  
Rolando Pedicini ◽  
José Ricardo Cezar Salgado ◽  
Priscilla Paiva Luz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Catalysts ◽  
Carbon Support ◽  
X Ray Diffraction ◽  
Direct Ethanol Fuel Cell ◽  
Pd Catalysts ◽  
Bifunctional Mechanism ◽  
Catalytic Activities ◽  
Intrinsic Mechanism ◽  
Ternary Catalysts

AbstractPhysical and electrochemical properties of Pd catalysts combined with Ru and Mo on carbon support were investigated. To this end, Pd, Pd1.3Ru1.0, Pd3.2Ru1.3Mo1.0 and Pd1.5Ru0.8Mo1.0 were synthesized on Carbon Vulcan XC72 support by the method of thermal decomposition of polymeric precursors and then physically and electrochemically characterized. The highest reaction yields are obtained for Pd3.2Ru1.3Mo1.0/C and Pd1.5Ru0.8Mo1.0/C and, as demonstrated by thermal analysis, they also show the smallest metal/carbon ratio compared the other catalysts. XRD (X-ray Diffraction) and Raman analyses show the presence of PdO and RuO2 for the Pd/C and the Pd1.3Ru1.0/C catalysts, respectively, a fact not observed for the Pd3.2Ru1.3 Mo1.0 /C and the Pd1.5Ru0.8Mo1.0/C catalysts. The catalytic activities were tested for the ethanol oxidation in alkaline medium. Cyclic voltammetry (CV) shows Pd1.3Ru1.0/C exhibiting the highest peak of current density, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. From, chronoamperometry (CA), it is possible to observe the lowest rate of poisoning for the Pd1.3Ru1.0/C, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. These results suggested that catalytic activity of the binary and the ternary catalysts are improved in comparison with Pd/C. The presence of RuO2 activated the bifunctional mechanism and improved the catalytic activity in the Pd1.3Ru1.0/C catalyst. The addition of Mo in the catalysts enhanced the catalytic activity by the intrinsic mechanism, suggesting a synergistic effect between metals. In summary, we suggest that it is possible to synthesize ternary PdRuMo catalysts supported on Carbon Vulcan XC72, resulting in materials with lower poisoning rates and lower costs than Pd/C. Graphic abstract

Activated carbon nanofibers incorporated metal oxides for CO2 adsorption: Effects of different type of metal oxides

2021 ◽  
Vol 45 ◽  
pp. 101434
Author(s):  
Faten Ermala Che Othman ◽  
Norhaniza Yusof ◽  
Sadaki Samitsu ◽  
Norfadhilatuladha Abdullah ◽  
Muhammad Faris Hamid ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Metal Oxides ◽  
Carbon Nanofibers ◽  
Co2 Adsorption ◽  
Activated Carbon Nanofibers ◽  
Adsorption Effects

scholarly journals Control of hydrogen release during borohydride electrooxidation with porous carbon materials

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15639-15655
Author(s):  
Małgorzata Graś ◽  
Grzegorz Lota
Keyword(s):  
Porous Carbon ◽  
Carbon Materials ◽  
Catalyst Support ◽  
Hydrogen Release ◽  
Technological Application ◽  
Porous Carbon Materials ◽  
Borohydride Electrooxidation

The borohydride electrooxidation process is complex. Technological application of carbon materials is manifested not only in their use as a catalyst support, but also as a physical trap for hydrogen generated during the parasitic hydrolysis.

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