Supported cobalt oxide nanocrystals: morphology control and catalytic performance for styrene oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89503-89509 ◽  
Author(s):  
Zhen Wang ◽  
Xianliang Hou ◽  
Jingmei Shen ◽  
Tiehu Li
Keyword(s):  
High Activity ◽  
Cobalt Oxide ◽  
Morphology Control ◽  
Catalytic Performance ◽  
Oxide Catalysts ◽  
Styrene Oxidation

Supported cobalt oxide catalysts with controlled size and morphologies were facilely synthesized and had high activity for styrene oxidation.

scholarly journals The Effect of Calcination Temperature on Cobalt Oxide Species and Performance for Catalytic Ozonation of NH4+ in Water

2019 ◽  
Vol 4 (3) ◽  
pp. 225
Author(s):  
Lina Mahardiani
Keyword(s):  
High Temperature ◽  
High Activity ◽  
Cobalt Oxide ◽  
Calcination Temperature ◽  
High Selectivity ◽  
Catalytic Performance ◽  
Catalytic Ozonation ◽  
Oxide Catalysts ◽  
Gas Products ◽  
And Performance

<p>Cobalt oxide catalysts can be prepared by impregnation and calcined under different temperature to obtained different species of cobalt oxide, namely CoO(OH), Co<sub>3</sub>O<sub>4</sub>, and CoO. Co<sub>3</sub>O<sub>4</sub> was the most appropriate catalyst for decomposing NH<sub>4</sub><sup>+</sup> with O<sub>3</sub> in the presence of Cl<sup>–</sup> because of relatively high activity, 74%, and high selectivity for gas products, 88%, compared to CoO and CoO(OH). Cl<sup>–</sup> is necessary to proceed the catalytic ozonation of NH<sub>4</sub><sup>+</sup> since Cl<sup>–</sup> participate in the catalytic ozonation mechanism, while SO<sub>4</sub><sup>2–</sup> inhibited the process. During the catalytic ozonation of NH<sub>4</sub><sup>+</sup>, Co<sub>3</sub>O<sub>4</sub> showed no deactivation rather than enhanced the catalytic performance after repeated used up to 100% of NH<sub>4</sub><sup>+</sup> conversion. The Co<sub>3</sub>O<sub>4</sub> can be regenerated by recalcining the catalyst under air at high temperature.</p>

Copper–cobalt oxide catalysts supported on MgF or AlO—their structure and catalytic performance

2006 ◽  
Vol 298 ◽  
pp. 225-231 ◽  
Author(s):  
M WOJCIECHOWSKA ◽  
M ZIELINSKI ◽  
A MALCZEWSKA ◽  
W PRZYSTAJKO ◽  
M PIETROWSKI
Keyword(s):  
Cobalt Oxide ◽  
Catalytic Performance ◽  
Oxide Catalysts

Cobalt oxide promoted tin oxide catalysts for highly selective glycerol acetalization reaction

2021 ◽  
Vol 128 ◽  
pp. 108578
Author(s):  
Semakaleng Bewana ◽  
Matumuene Joe Ndolomingo ◽  
Reinout Meijboom ◽  
Ndzondelelo Bingwa
Keyword(s):  
Cobalt Oxide ◽  
Tin Oxide ◽  
Oxide Catalysts ◽  
Acetalization Reaction

scholarly journals Effects of Annealing Temperature on the Oxygen Evolution Reaction Activity of Copper–Cobalt Oxide Nanosheets

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 657
Author(s):  
Geul Han Kim ◽  
Yoo Sei Park ◽  
Juchan Yang ◽  
Myeong Je Jang ◽  
Jaehoon Jeong ◽  
...  
Keyword(s):  
High Activity ◽  
Cobalt Oxide ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Cobalt Hydroxide ◽  
Ni Foam ◽  
Electron Conduction

Developing high performance, highly stable, and low-cost electrodes for the oxygen evolution reaction (OER) is challenging in water electrolysis technology. However, Ir- and Ru-based OER catalysts with high OER efficiency are difficult to commercialize as precious metal-based catalysts. Therefore, the study of OER catalysts, which are replaced by non-precious metals and have high activity and stability, are necessary. In this study, a copper–cobalt oxide nanosheet (CCO) electrode was synthesized by the electrodeposition of copper–cobalt hydroxide (CCOH) on Ni foam followed by annealing. The CCOH was annealed at various temperatures, and the structure changed to that of CCO at temperatures above 250 °C. In addition, it was observed that the nanosheets agglomerated when annealed at 300 °C. The CCO electrode annealed at 250 °C had a high surface area and efficient electron conduction pathways as a result of the direct growth on the Ni foam. Thus, the prepared CCO electrode exhibited enhanced OER activity (1.6 V at 261 mA/cm2) compared to those of CCOH (1.6 V at 144 mA/cm2), Co3O4 (1.6 V at 39 mA/cm2), and commercial IrO2 (1.6 V at 14 mA/cm2) electrodes. The optimized catalyst also showed high activity and stability under high pH conditions, demonstrating its potential as a low cost, highly efficient OER electrode material.

Fabrication of Hollow Silica-Alumina Composite Spheres Using L(+)-Arginine and their Catalytic Performance for Hydrolytic Dehydrogenation of Ammonia Borane

2014 ◽  
Vol 617 ◽  
pp. 170-173
Author(s):  
Tetsuo Umegaki ◽  
Shunsuke Imamura ◽  
Naoki Toyama ◽  
Qiang Xu ◽  
Yoshiyuki Kojima
Keyword(s):  
High Activity ◽  
Sol Gel ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Ammonia Borane ◽  
Catalytic Performance ◽  
Hollow Silica ◽  
Silica Alumina ◽  
Alumina Composite ◽  
Composite Walls

The present study reports a facile and effective approach for fabrication of hollow silica-alumina composite spheres. In this approach, silica-alumina composite walls were coated on polystyrene template by the sol-gel method using L(+)-arginine as a promoter for the reaction followed by calcination procedure. Using L(+)-arginine as a promoter of coating process, homogeneous hollow silica-alumina composite spheres are obtained and the wall thickness is larger than that of the hollow spheres prepared with ammonia. The hollow spheres shows high activity for hydrolytic dehydrogenation of ammonia borane compared with spherical silica-alumina composite particles without hollow structure, the hollow spheres prepared with ammonia, and conventional H-BEA zeolite. The results indicate that hollow structure plays important role to show high activity.

scholarly journals Statistically Guided Synthesis of MoV-Based Mixed-Oxide Catalysts for Ethane Partial Oxidation

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 370
Author(s):  
Juan Jimenez ◽  
Kathleen Mingle ◽  
Teeraya Bureerug ◽  
Cun Wen ◽  
Jochen Lauterbach
Keyword(s):  
Acetic Acid ◽  
Partial Oxidation ◽  
Mixed Oxide ◽  
Structural Integrity ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Oxide Catalysts ◽  
Acid Yield ◽  
Mixed Oxide Catalysts ◽  
Catalyst Composition

The catalytic performance of Mo8V2Nb1-based mixed-oxide catalysts for ethane partial oxidation is highly sensitive to the doping of elements with redox and acid functionality. Specifically, control over product distributions to ethylene and acetic acid can be afforded via the specific pairing of redox elements (Pd, Ni, Ti) and acid elements (K, Cs, Te) and the levels at which these elements are doped. The redox element, acid element, redox/acid ratio, and dopant/host ratio were investigated using a three-level, four-factor factorial screening design to establish relationships between catalyst composition, structure, and product distribution for ethane partial oxidation. Results show that the balance between redox and acid functionality and overall dopant level is important for maximizing the formation of each product while maintaining the structural integrity of the host metal oxide. Overall, ethylene yield was maximized for a Mo8V2Nb1Ni0.0025Te0.5 composition, while acetic acid yield was maximized for a Mo8V2Nb1Ti0.005Te1 catalyst.

scholarly journals Catalytic Abatement of Volatile Organic Compounds and Soot over Manganese Oxide Catalysts

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4534
Author(s):  
Miguel Jose Marin Figueredo ◽  
Clarissa Cocuzza ◽  
Samir Bensaid ◽  
Debora Fino ◽  
Marco Piumetti ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Low Temperature ◽  
Manganese Oxide ◽  
Organic Compounds ◽  
Catalytic Performance ◽  
Oxide Catalysts ◽  
X Ray ◽  
Manganese Oxide Catalysts ◽  
Volatile Organic ◽  
Temperature Programmed

A set of manganese oxide catalysts was synthesized via two preparation techniques: solution combustion synthesis (Mn3O4/Mn2O3-SCS and Mn2O3-SCS) and sol-gel synthesis (Mn2O3-SG550 and Mn2O3-SG650). The physicochemical properties of the catalysts were studied by means of N2-physisorption at −196 °C, X-ray powder diffraction, H2 temperature-programmed reduction (H2-TPR), soot-TPR, X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM). The high catalytic performance of the catalysts was verified in the oxidation of Volatile Organic Compounds (VOC) probe molecules (ethene and propene) and carbon soot in a temperature-programmed oxidation setup. The best catalytic performances in soot abatement were observed for the Mn2O3-SG550 and the Mn3O4/Mn2O3-SCS catalysts. The catalytic activity in VOC total oxidation was effectively correlated to the enhanced low-temperature reducibility of the catalysts and the abundant surface Oα-species. Likewise, low-temperature oxidation of soot in tight contact occurred over the Mn2O3-SG550 catalyst and was attributed to high amounts of surface Oα-species and better surface reducibility. For the soot oxidation in loose contact, the improved catalytic performance of the Mn3O4/Mn2O3-SCS catalyst was attributed to the beneficial effects of both the morphological structure that—like a filter—enhanced the capture of soot particles and to a probable high amount of surface acid-sites, which is characteristic of Mn3O4 catalysts.

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