scholarly journals H2-TPR, XPS and TEM Study of the Reduction of Ru and Re promoted Co/γ-Al2O3, Co/TiO2 and Co/SiC Catalysts

2016 ◽  
Vol 5 (2) ◽  
pp. 39 ◽  
Author(s):  
H. Romar ◽  
A. H. Lillebo ◽  
P. Tynjala ◽  
T. Hu ◽  
A. Holmen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metallic Nanoparticles ◽  
Surface Composition ◽  
Active Phase ◽  
Support Materials ◽  
Metal Support Interaction ◽  
Active Metal ◽  
Metal Support ◽  
Oxide Phases

<p class="1Body">Effects of Ru and Re promoters on Co-CoO<sub>x </sub>catalysts supported on γ-Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub> and SiC were investigated to improve the understanding of the role of promoters of the active phase of Co-CoO<sub>x</sub>-Ru and Co-CoO<sub>x</sub>-Re. The influence of promoter addition on the composition and activity of the catalysts was characterized by several methods, such as H<sub>2</sub>-TPR, XPS, chemisorption and TEM. Furthermore, the role of support and metal-support interaction was especially studied and different support materials were compared.</p><p class="1Body">Based on the results, addition of promoter metals (Ru or Re) will most likely improve catalytic activity of Co/γ-Al<sub>2</sub>O<sub>3</sub>, Co/TiO<sub>2</sub> and Co/SiC catalysts by increasing the active metal surface available for chemical reaction and by decreasing the size of the metallic nanoparticles. These changes in the catalytic activity were also associated with the changes in the ratio of metal and metal oxide phases in the surface composition as observed by XPS. Promoter metals also decreased the reduction temperatures needed for the reduction of Co<sub>3</sub>O<sub>4</sub> to CoO and further to metallic cobalt. Significant decrease in reduction temperature was observed especially when ruthenium was used as the promoter.</p>

scholarly journals H2-TPR, XPS and TEM Study of the Reduction of Ru and Re promoted Co/γ-Al2O3, Co/TiO2 and Co/SiC Catalysts

2016 ◽  
Vol 5 (2) ◽  
pp. 33 ◽  
Author(s):  
H. Romar ◽  
A. H. Lillebo ◽  
P. Tynjala ◽  
T. Hu ◽  
A. Holmen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metallic Nanoparticles ◽  
Surface Composition ◽  
Active Phase ◽  
Support Materials ◽  
Metal Support Interaction ◽  
Active Metal ◽  
Metal Support ◽  
Oxide Phases

<p class="1Body">Effects of Ru and Re promoters on Co-CoO<sub>x </sub>catalysts supported on γ-Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub> and SiC were investigated to improve the understanding of the role of promoters of the active phase of Co-CoO<sub>x</sub>-Ru and Co-CoO<sub>x</sub>-Re. The influence of promoter addition on the composition and activity of the catalysts was characterized by several methods, such as H<sub>2</sub>-TPR, XPS, chemisorption and TEM. Furthermore, the role of support and metal-support interaction was especially studied and different support materials were compared.</p><p class="1Body">Based on the results, addition of promoter metals (Ru or Re) will most likely improve catalytic activity of Co/γ-Al<sub>2</sub>O<sub>3</sub>, Co/TiO<sub>2</sub> and Co/SiC catalysts by increasing the active metal surface available for chemical reaction and by decreasing the size of the metallic nanoparticles. These changes in the catalytic activity were also associated with the changes in the ratio of metal and metal oxide phases in the surface composition as observed by XPS. Promoter metals also decreased the reduction temperatures needed for the reduction of Co<sub>3</sub>O<sub>4</sub> to CoO and further to metallic cobalt. Significant decrease in reduction temperature was observed especially when ruthenium was used as the promoter.</p>

Trimetallic RuxMoNi Catalysts Supported on SBA-15 for the Hydrodesulfurization of Dibenzothiophene

2018 ◽  
Vol 17 (5) ◽  
Author(s):  
N.L. Torres-García ◽  
R. Huirache-Acuña ◽  
T.A. Zepeda-Partida ◽  
B. Pawelec ◽  
J.L.G. Fierro ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Catalytic Activity ◽  
Chelating Agent ◽  
Active Phase ◽  
Atomic Ratio ◽  
Support Interaction ◽  
Micro Raman Spectroscopy ◽  
Metal Support Interaction ◽  
Sulfided Catalysts ◽  
Metal Support

Abstract In this work, novel trimetallic catalysts based on transition metal sulphides (Ru, Mo and Ni) supported on SBA-15 were synthesized. Citric acid (CA) was used as chelating agent in order to enhance the dispersion of the active phase and minimize the metal-support interaction. Sulfided catalysts were evaluated in the reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT) at 320 °C and 54.5 atm of total H2 pressure. The effects of different Ru/(Ni + Mo) atomic ratios on the active phase were studied. The catalysts were characterized using Micro-Raman spectroscopy, DRIFTS, XRD, XPS, HR-TEM and SEM techniques. Results have shown that there was a better dispersion of the metallic phases, which improves the physicochemical properties of the catalysts, increasing the catalytic activity. The trimetallic RuxMoNi catalyst with the lowest atomic ratio, have shown superior catalytic activity compared to their higher atomic ratio counterparts. The interaction of the chelating agent improved the catalytic activity, which was superior to that observed for NiMo based catalysts, considered one of the most active hydrotreating catalysts.

The role of metal–support interaction in catalytic activity of nanodiamond-supported nickel in selective phenylacetylene hydrogenation

2016 ◽  
Vol 344 ◽  
pp. 90-99 ◽  
Author(s):  
E.V. Golubina ◽  
E.S. Lokteva ◽  
A.V. Erokhin ◽  
A.A. Veligzhanin ◽  
Ya.V. Zubavichus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support

Effects of rare earth metal doping on Au/ReZrO2 catalysts for efficient hydrogen generation from formic acid

2021 ◽  
Vol 45 (12) ◽  
pp. 5704-5711
Author(s):  
Luming Wu ◽  
Yu Hao ◽  
Shaohua Chen ◽  
Rui Chen ◽  
Pingchuan Sun ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rare Earth ◽  
Rare Earth Metal ◽  
Oxygen Vacancies ◽  
Hydrogen Generation ◽  
Earth Metal ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Metal Doped

Rare earth metal doped ZrO2 can promote the formation of oxygen vacancies in zirconia, which enhances the metal–support interaction, finally promoting catalytic activity of FA dehydrogenation.

scholarly journals Role of CO2 During Oxidative Dehydrogenation of Propane Over Bulk and Activated-Carbon Supported Cerium and Vanadium Based Catalysts

2021 ◽  
Author(s):  
Petar Djinović ◽  
Janez Zavašnik ◽  
Janvit Teržan ◽  
Ivan Jerman
Keyword(s):  
Catalytic Activity ◽  
Activated Carbon ◽  
Oxidative Dehydrogenation ◽  
Active Phase ◽  
Lattice Oxygen ◽  
Chemisorbed Oxygen ◽  
Catalytically Active ◽  
Temperature Programmed ◽  
Propane Cracking

AbstractCeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested in propane oxidative dehydrogenation using CO2. Complete oxidation of propane to CO and CO2 is favoured by lattice oxygen of CeO2. The temperature programmed experiments show the ~ 4 nm AC supported CeO2 crystallites become more susceptible to reduction by propane, but less prone to re-oxidation with CO2 compared to bulk CeO2. Catalytic activity of CeVO4/AC catalysts requires a 1–2 nm amorphous CeVO4 layer. During reaction, the amorphous CeVO4 layer crystallises and several atomic layers of carbon cover the CeVO4 surface, resulting in deactivation. During reaction, V2O5 is irreversibly reduced to V2O3. The lattice oxygen in bulk V2O5 favours catalytic activity and propene selectivity. Bulk V2O3 promotes only propane cracking with no propene selectivity. In VOx/AC materials, vanadium carbide is the catalytically active phase. Propane dehydrogenation over VC proceeds via chemisorbed oxygen species originating from the dissociated CO2. Graphic Abstract

scholarly journals Ag/CeO2 Composites for Catalytic Abatement of CO, Soot and VOCs

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 285 ◽  
Author(s):  
M. Grabchenko ◽  
N. Mikheeva ◽  
G. Mamontov ◽  
M. Salaev ◽  
L. Liotta ◽  
...  
Keyword(s):  
Noble Metals ◽  
Chemical Properties ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Defective Structure ◽  
Metal Support Interaction ◽  
Key Factor ◽  
Metal Support ◽  
Vocs Abatement

Nowadays catalytic technologies are widely used to purify indoor and outdoor air from harmful compounds. Recently, Ag–CeO2 composites have found various applications in catalysis due to distinctive physical-chemical properties and relatively low costs as compared to those based on other noble metals. Currently, metal–support interaction is considered the key factor that determines high catalytic performance of silver–ceria composites. Despite thorough investigations, several questions remain debating. Among such issues, there are (1) morphology and size effects of both Ag and CeO2 particles, including their defective structure, (2) chemical and charge state of silver, (3) charge transfer between silver and ceria, (4) role of oxygen vacancies, (5) reducibility of support and the catalyst on the basis thereof. In this review, we consider recent advances and trends on the role of silver–ceria interactions in catalytic performance of Ag/CeO2 composites in low-temperature CO oxidation, soot oxidation, and volatile organic compounds (VOCs) abatement. Promising photo- and electrocatalytic applications of Ag/CeO2 composites are also discussed.

Sign in / Sign up

Export Citation Format

Share Document