Novel Carbon Structure as Highly Stable Support for Electro-catalyst in Acid Media: Regulating Oxygen Functionalization Behavior of Carbon

2021 ◽  
Author(s):  
Guokang Han ◽  
Yongrong Sun ◽  
Yuxin Liu ◽  
Lingfeng Li ◽  
Xudong Li ◽  
...  
Keyword(s):  
Precious Metal ◽  
Catalytic Properties ◽  
Supported Catalysts ◽  
Carbon Support ◽  
Carbon Structure ◽  
Acid Media

The nature of carbon support has huge effects on the catalytic properties of supported catalysts. When utilized for electrochemical purposes as support for precious metal in acid media, the oxygen...

scholarly journals Towards High Efficacy of Pd-Au/C Catalyst for Tetrachloromethane Hydrodechlorination

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 338-359
Author(s):  
Magdalena Bonarowska ◽  
Zbigniew Kaszkur ◽  
Krzysztof Matus ◽  
Alicja Drelinkiewicz ◽  
Tomasz Szumełda ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Gas Phase ◽  
Thermal Activation ◽  
Supported Catalysts ◽  
Carbon Support ◽  
Thermal Reduction ◽  
Microwave Oven ◽  
Optimal Conditions ◽  
Catalyst Activation ◽  
Critical Part

We present an efficient strategy for synthesising the PdAu catalysts with a homogeneous PdAu alloy phase for environmentally important hydrodechlorination of tetrachloromethane in the gas phase. The synthesis of carbon-supported catalysts involved two major steps: (i) incorporation of palladium and gold nanoparticles into carbon support and (ii) activation of the catalysts. The critical part of this work was to find the optimal conditions for both steps. Thus, the incorporation of the nanoparticles was carried out in two ways, by impregnation and direct redox reaction method using acetone solutions of metal precursor salts. The activation was performed either by a conventional thermal reduction in hydrogen or flash irradiation in a microwave oven. The homogeneity and structure of the PdAu alloy were found to depend on the catalyst activation method critically. In all cases, we observed better homogeneity for catalysts that were subject to microwave irradiation. Moreover, the flash microwave irradiation of prepared catalysts provided catalysts of better stability and selectivity towards the desired products (hydrocarbons) in the hydrodechlorination of tetrachloromethane as compared to the catalyst obtained by conventional thermal activation in hydrogen.

Synthesis, characterization and catalytic properties of polypyrrole-supported catalysts

2003 ◽  
Vol 4 (8) ◽  
pp. 435-439 ◽  
Author(s):  
Eric Gautron ◽  
Anthony Garron ◽  
Emmanuelle Bost ◽  
Florence Epron
Keyword(s):  
Catalytic Properties ◽  
Supported Catalysts

scholarly journals Surfactant-Free Colloidal Strategies for Highly Dispersed and Active Supported IrO2 Catalysts: Synthesis and Performance Evaluation for the Oxygen Evolution Reaction

2021 ◽  
Author(s):  
Francesco Bizzotto ◽  
Jonathan Quinson ◽  
Johanna Schröder ◽  
Alessandro Zana ◽  
Matthias Arenz
Keyword(s):  
Supported Catalysts ◽  
Active Phase ◽  
Carbon Support ◽  
Colloidal Dispersions ◽  
Catalyst Design ◽  
Transition Electron Microscopy ◽  
Highly Active ◽  
X Ray Scattering ◽  
And Performance ◽  
Transition Electron

Supported Ir oxide catalysts obtained from surfactant-free colloidal Ir nanoparticles (NPs) synthesized in alkaline methanol (MeOH), ethanol (EtOH), and ethylene glycol (EG) are investigated and compared. The comparison of independent techniques such as transition electron microscopy (TEM), small angle X-ray scattering (SAXS), and electrochemistry allows shedding light on the parameters that affect the dispersion of the active phase as well as the catalytic activity. The colloidal dispersions obtained are suitable to develop supported catalysts with little NP agglomeration on a carbon support leading to highly active catalysts with more than 400 A g<sup>-1</sup><sub>Ir</sub> reached at 1.5 V<sub>RHE</sub> for the OER. While the more common surfactant-free alkaline EG synthesis requires flocculation and re-dispersion leading to Ir loss, the main difference between methanol and ethanol as solvent is related to the dispersibility of the support material. The choice of the suitable monoalcohol determines the maximum achieved Ir loading on the support without detrimental particle agglomeration. This simple consideration on catalyst design can readily lead to significantly improved catalysts.

scholarly journals A Phenomenological Study on the Synergistic Role of Precious Metals in the Steam Reforming of Logistic Fuels on Trimetal-Supported Catalysts

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Abdul-Majeed Azad ◽  
Desikan Sundararajan
Keyword(s):  
Steam Reforming ◽  
Precious Metal ◽  
Noble Metals ◽  
Phenomenological Study ◽  
Supported Catalysts ◽  
Precious Metals ◽  
Jet Fuels ◽  
Metal Loading

Fuel processors are required to convert sulfur-laden logistic fuels (jet fuels, diesel, and coal) into fuel cell quality hydrogen-rich reformate with little or no sulfur for extended periods. Sulfur poisons and deactivates the reforming catalyst, therefore, sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization, and evaluation of a series of nanoscale ceria-supported reforming catalysts containing three noble metals in low concentration (1 wt% ≤ total metal loading ≤ 1.33 wt%) for the steam-reforming of kerosene (a JP-8 surrogate) are reported. Their performance is quantified in terms of H2yield, tolerance towards sulfur in the fuel, and the on-stream stability and compared with that of monometal and bimetal analogs under identical conditions. Due to the inherent cooperative synergy, a trimetal catalyst was found far superior to its mono- and bimetallic analog containing same amount of the precious metal loading in terms of quality of the reformate (measured by H2level in steady-state) as well as the catalyst longevity on-stream prior to deactivation. At the same time a mechanistic correlation between the distinct role of a given precious metal and the extent of its loading in each of the formulations and quality of the corresponding desulfurized H2-rich reformate was discovered.

XRD characterization of highly dispersed metal catalysts on carbon support

1993 ◽  
Vol 8 (8) ◽  
pp. 1829-1835 ◽  
Author(s):  
Paolo Scardi ◽  
Pier Luigi Antonucci
Keyword(s):  
Particle Size ◽  
Supported Catalysts ◽  
Profile Analysis ◽  
Rietveld Method ◽  
Carbon Support ◽  
Lattice Parameter ◽  
Microstructural Parameters ◽  
Transmission Electron ◽  
Supported Pt Catalysts ◽  
Highly Dispersed

Carbon-supported Pt catalysts were prepared from H2PtCl6 or K2PtCl6 aqueous solutions. Particle size and structure after several thermal activation treatments were studied by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Cyclic Voltammetry (CV), and the results of the three techniques were compared. As the catalysts were highly dispersed on an amorphous support, a conventional XRD profile analysis for crystallite size determination could not be performed properly, because of the strong overlapping between the broad Pt peaks superposed to the halos of the amorphous phase. Thus, a new procedure of whole XRD pattern fitting, based on the Rietveld method, was used to have reliable data of Pt particle size (surface area) and lattice parameter. All structural and microstructural parameters were refined within the same procedure, also considering the transparency of the carbon supported catalysts and minimizing the effect of the amorphous background. The method can also take into account the presence of bimodal particle size distributions, which is difficult to study by CV or TEM.

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