Augmenting the catalytic activity of CoFe2O4 by substituting rare earth cations into the spinel structure

RSC Advances ◽  
2016 ◽  
Vol 6 (75) ◽  
pp. 71676-71691 ◽  
Author(s):  
Rimi Sharma ◽  
S. Bansal ◽  
Sonal Singhal
Keyword(s):  
Catalytic Activity ◽  
Rare Earth ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Research Work ◽  
Significant Enhancement

The current research work evaluates significant enhancement in photo-Fenton activity of pristine cobalt ferrite (CoFe2O4) by inserting very small quantity of rare earth cations such as cerium (Ce3+) and lanthanum (La3+) into its spinel structure.

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.

Densely populated mesopores in microcuboid CeO2crystal leading to a significant enhancement of catalytic activity

2013 ◽  
Vol 1 (3) ◽  
pp. 728-734 ◽  
Author(s):  
Wenqin Shi ◽  
Yuanzhi Li ◽  
Jingtao Hou ◽  
Haiqin Lv ◽  
Xiujian Zhao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Significant Enhancement

Samarium Ions Concentration Dependent Optical Enhancement in Phosphate Glass

2015 ◽  
Vol 1107 ◽  
pp. 449-453
Author(s):  
Ramli Arifin ◽  
Lee Pei San ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal ◽  
Khaidzir Hamzah
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Absorption Spectra ◽  
Phosphate Glass ◽  
Emission Spectra ◽  
Photonic Devices ◽  
Phosphate Glasses ◽  
Significant Enhancement ◽  
Melt Quenching ◽  
Nir Absorption

Glasses activated rare earth (RE) ions are demanding for photonic devices. Optimization of rare earth dopants, chemical composition of glass former and modifier decides spectra features. We synthesize a series of glass having composition (50-x)P2O5 - 30Li2O - 20Na2O - (x)Sm2O3, where x = 0 to 2.0 mol% (optimizing RE concentration) via melt-quenching technique. The effects of Sm2O3 concentration on significant enhancement of absorption and luminescence are scrutinized. The UV-Vis-NIR absorption spectra reveal ten band and the emission spectra exhibit four peaks specific to the dopant. The results suggest that samarium doped phosphate glasses are potential for laser and other applications.

A Magnetically Ordered Non-Stoichiometric Zinc Ferrite for the Oxidative Dehydrogenation Reactions.

2001 ◽  
Vol 676 ◽  
Author(s):  
J. A. Toledo ◽  
N. Nava ◽  
X. C. Sun ◽  
X. Bokhimi
Keyword(s):  
Catalytic Activity ◽  
Oxidative Dehydrogenation ◽  
Spinel Structure ◽  
Zinc Ferrite ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Octahedral Sites ◽  
Tetrahedral Sites ◽  
Dehydrogenation Reactions ◽  
Hydrothermal Reduction

ABSTRACTZnFe2O4 nanoparticles were prepared by hydrothermal reduction approach. A considerable amount of α-Fe2O3 was segregated in the as-synthesized sample, which diffused into the tetrahedral and octahedral sites of the ZnFe2O4 spinel structure with increasing the annealing temperature. The introduction of Fe3+ into the tetrahedral positions was observed by Mössbauer spectra. Magnetization measurements showed an unusual ferrimagnetic behavior of the ZnFe2O4 phase, even at room temperature, confirming the introduction of Fe3+ into the tetrahedral sites of the spinel structure. Catalytic activity measured in the oxidative dehydrogenation of 1-butene reaction increased with increasing annealing temperature, indicating that those interactions of Fe3+ in tetrahedral and octahedral positions also promotes the activity and selectivity to butadiene formation.

Theoretical insights into the effective hydrogen evolution on Cu3P and its evident improvement by surface-doped Ni atoms

2018 ◽  
Vol 20 (15) ◽  
pp. 10407-10417 ◽  
Author(s):  
Zengsong Zhang ◽  
Guangtao Yu ◽  
Hui Li ◽  
Jingwei Liu ◽  
Xuri Huang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Deep Understanding ◽  
Atomic Level ◽  
Significant Enhancement ◽  
Effective Hydrogen

Deep understanding at the atomic level of the HER catalytic activity of Cu3P and its significant enhancement by surface-doped Ni atoms.

Synthesis of Isopulegol Through Cyclisation of Citronellal Using Solid Acid Catalysts: Catalytic Reaction Performance Evaluation and Process Parameters Optimization

2021 ◽  
Vol 22 (2) ◽  
pp. 252-263
Author(s):  
Abdul Karim Shah ◽  
Ghulam Abbas Kandhro ◽  
Aqeel Ahmed Shah ◽  
Syed Nizam Uddin Shah Bukhari ◽  
Arshad Iqbal ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Process Parameters ◽  
Acid Treatment ◽  
Research Work ◽  
Intermediate Stage ◽  
Catalytic Performance ◽  
Montmorillonite Clay ◽  
Parameters Optimization ◽  
Reaction Performance ◽  
Montmorillonite Catalyst

The cyclisation of citronellal to isopulegol is a significant intermediate stage in the production of menthols. In this research work, the effects of acid treatment on montmorillonite clay have been investigated and used in citronellal cyclisation reactions. Furthermore, the effects of acid treatment and hetero-poly acid impregnation have been determined on the textural and catalytic properties of montmorillonite clay. The designed catalysts were characterized by XRD, N2 sorption, and NH3- TPD techniques. Acid treatment of montmorillonite resulted in the enhancement of surface area and pore volume. The catalytic activity and selectivity parameters were lessened due to the severe leaching of Al ions from tetrahedral crystalline structures (e.g., weakened structure and loss of acidity). Among all prepared materials, the heteropoly acid supported HCl treated montmorillonite catalyst was observed as a more active, stable, and selective catalyst that showed the highest catalytic performance in citronellal cyclisation under optimized process parameters. The catalytic activity and selectivity were enhanced with rising mesoporosity and acidity parameters due to HCl acid treatment and HPA impregnation.

scholarly journals Copper-Containing Mixed Metal Oxides (Al, Fe, Mn) for Application in Three-Way Catalysis

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1344
Author(s):  
Tim Van Everbroeck ◽  
Radu-George Ciocarlan ◽  
Wouter Van Hoey ◽  
Myrjam Mertens ◽  
Pegie Cool
Keyword(s):  
Catalytic Activity ◽  
Spinel Structure ◽  
Mixed Oxides ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Application ◽  
Mixed Spinel ◽  
Co Precipitation ◽  
Three Way Catalysis

Mixed oxides were synthesized by co-precipitation of a Cu source in combination with Al, Fe or Mn corresponding salts as precursors. The materials were calcined at 600 and 1000 °C in order to crystallize the phases and to mimic the reaction conditions of the catalytic application. At 600 °C a mixed spinel structure was only formed for the combination of Cu and Mn, while at 1000 °C all the materials showed mixed spinel formation. The catalysts were applied in three-way catalysis using a reactor with a gas mixture containing CO, NO and O2. All the materials calcined at 600 °C displayed the remarkable ability to oxidize CO with O2 but also to reduce NO with CO, while the pure oxides such as CuO and MnO2 were not able to. The high catalytic activity at 600 °C was attributed to small supported CuO particles present and imperfections in the spinel structure. Calcination at 1000 °C crystallized the structure further which led to a dramatic loss in catalytic activity, although CuAl2O4 and CuFe2O4 still converted some NO. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, H2-Temperatrue Programmed Reduction (H2-TPR), N2-sorption and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX).

Sign in / Sign up

Export Citation Format

Share Document