scholarly journals Influence of Carbon Support on Electronic Structure and Catalytic Activity of Pt Catalysts: Binding to the CO Molecule

2016 ◽  
Vol 120 (23) ◽  
pp. 12452-12462 ◽  
Author(s):  
Mehdi Mahmoodinia ◽  
Per-Olof Åstrand ◽  
De Chen
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
Carbon Support ◽  
Pt Catalysts

Alloy tetrahexahedral Pd–Pt catalysts: enhancing significantly the catalytic activity by synergy effect of high-index facets and electronic structure

2012 ◽  
Vol 3 (4) ◽  
pp. 1157 ◽  
Author(s):  
Yu-Jia Deng ◽  
Na Tian ◽  
Zhi-You Zhou ◽  
Rui Huang ◽  
Zi-Li Liu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
High Index ◽  
Pt Catalysts ◽  
Synergy Effect

scholarly journals Influence of the Reduction Temperature and the Nature of the Support on the Performance of Zirconia and Alumina-Supported Pt Catalysts for n-Dodecane Hydroisomerization

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Diana García-Pérez ◽  
Maria Consuelo Alvarez-Galvan ◽  
Jose M. Campos-Martin ◽  
Jose L. G. Fierro
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
Catalytic Performance ◽  
Major Influence ◽  
Pt Catalysts ◽  
Reduction Temperature ◽  
Metal Dispersion ◽  
Tungsten Oxides ◽  
Supported Pt Catalysts

Catalysts based on zirconia- and alumina-supported tungsten oxides (15 wt % W) with a small loading of platinum (0.3 wt % Pt) were selected to study the influence of the reduction temperature and the nature of the support on the hydroisomerization of n-dodecane. The reduction temperature has a major influence on metal dispersion, which impacts the catalytic activity. In addition, alumina and zirconia supports show different catalytic properties (mainly acid site strength and surface area), which play an important role in the conversion. The NH3-TPD profiles indicate that the acidity in alumina-based catalysts is clearly higher than that in their zirconia counterparts; this acidity can be attributed to a stronger interaction of the WOx species with alumina. The PtW/Al catalyst was found to exhibit the best catalytic performance for the hydroisomerization of n-dodecane based on its higher acidity, which was ascribed to its larger surface area relative to that of its zirconia counterparts. The selectivity for different hydrocarbons (C7–10, C11 and i-C12) was very similar for all the catalysts studied, with branched C12 hydrocarbons being the main products obtained (~80%). The temperature of 350 °C was clearly the best reduction temperature for all the catalysts studied in a trickled-bed-mode reactor.

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

Electronic structure modulation of NiS2 by transition metal doping for accelerating the hydrogen evolution reaction

2019 ◽  
Vol 7 (9) ◽  
pp. 4971-4976 ◽  
Author(s):  
Tongtong Wang ◽  
Xiaosong Guo ◽  
Jingyan Zhang ◽  
Wen Xiao ◽  
Pinxian Xi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
Transition Metal ◽  
Hydrogen Evolution Reaction ◽  
Systematic Study ◽  
First Principles ◽  
Transition Metal Doping ◽  
First Principles Calculations ◽  
Structure Modulation ◽  
Metal Doped

We give a systematic study of the HER catalytic activity of transition metal doped NiS2 by first principles calculations and experiments.

Theoretical Insights into the Electronic Structure and Catalytic Activity on MoS2-Based Catalyst

2019 ◽  
pp. 41-59
Author(s):  
Xiaodong Wen ◽  
Tao Yang ◽  
Manuel Ramos ◽  
Gabriel A. Gonzalez ◽  
Russell R. Chianelli
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity

Small is different

2021 ◽  
pp. 81-93
Author(s):  
Adrian P Sutton
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Catalytic Activity ◽  
Giant Magnetoresistance ◽  
Energy Levels ◽  
Exclusion Principle ◽  
Thermodynamic Quantities ◽  
Discrete Energy ◽  
Size Dependent ◽  
The World

As the size of a material decreases to the nanoscale its properties become size-dependent. This is the world of nanoscience and nanotechnology. At the nanoscale the crystal structure may change and thermodynamic quantities such as the melting point also change. Changes in the catalytic activity and colour of nanoparticles suspended in a liquid indicate changes to the electronic structure. Quantum dots have discrete energy levels that can be modelled with the particle-in-a-box model. Excitons may be created in them using optical illumination, and their decay leads to fluorescence with distinct colours. The classical and quantum origins of magnetism are discussed. The origin of magnetoresistance in a ferromagnet is described and related to the exclusion principle. The origin of the giant magnetoresistance effect and its exploitation in nanotechnology is outlined.

scholarly journals Theoretical design of a technetium-like alloy and its catalytic properties

2019 ◽  
Vol 10 (21) ◽  
pp. 5461-5469
Author(s):  
Wei Xie ◽  
Michihisa Koyama
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Catalytic Activity ◽  
Density Of States ◽  
Phase Stability ◽  
Density Functional ◽  
Catalytic Properties ◽  
Functional Theory ◽  
Theoretical Design ◽  
Structure Phase

Based on the concept of density of states (DOS) engineering, we theoretically designed a pseudo-Tc material (Mo–Ru alloy) and investigated its electronic structure, phase stability and catalytic activity by using density functional theory.

scholarly journals Carbon-Supported Fe Catalysts forCO2Electroreduction to High-Added Value Products: A DEMS Study: Effect of the Functionalization of the Support

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
S. Pérez-Rodríguez ◽  
G. García ◽  
L. Calvillo ◽  
V. Celorrio ◽  
E. Pastor ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ethylene Glycol ◽  
Surface Chemistry ◽  
Physicochemical Properties ◽  
Electrochemical Properties ◽  
Textural Properties ◽  
Carbon Support ◽  
Product Distribution ◽  
Added Value ◽  
Fe Catalysts

Vulcan XC-72R-supported Fe catalysts have been synthesised for the electroreduction of CO2to high-added value products. Catalysts were obtained by the polyol method, using ethylene glycol as solvent and reducing agent. Prior to the metal deposition, Vulcan was subjected to different oxidation treatments in order to modify its surface chemistry and study its influence on the physicochemical and electrochemical properties of the catalysts, as well as on the product distribution. The oxidation treatments of the supports modify their textural properties, but do not affect significantly the physicochemical properties of catalysts. However, DEMS studies showed that the carbon support degradation, the distribution of products, and the catalytic activity toward the CO2electroreduction reaction depend significantly on the surface chemistry of the carbon support.

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