Redox Properties of Nanocrystalline Cu-Doped Cerium Oxide Studied by Isothermal Gravimetric Analysis and X-ray Photoelectron Spectroscopy

1999 ◽  
Vol 103 (42) ◽  
pp. 8858-8863 ◽  
Author(s):  
Andreas Tschöpe ◽  
Michel L. Trudeau ◽  
Jackie Y. Ying
Keyword(s):  
Cerium Oxide ◽  
Photoelectron Spectroscopy ◽  
Redox Properties ◽  
Gravimetric Analysis ◽  
X Ray

scholarly journals Magnetic γFe2O3@Sh@Cu2O: an efficient solid-phase catalyst for reducing agent and base-free click synthesis of 1,4-disubstituted-1,2,3-triazoles

BMC Chemistry ◽  
2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Fereshteh Norouzi ◽  
Shahrzad Javanshir
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Solid Phase ◽  
Click Reaction ◽  
Copper Acetate ◽  
Reducing Agent ◽  
Gravimetric Analysis ◽  
High Turnover ◽  
One Pot ◽  
X Ray

AbstractA hybrid magnetic material γFe2O3@Sh@cu2O was easily prepared from Shilajit (Sh) decorated Fe3O4 and copper acetate. The prepared magnetic hybrid material was fully characterized using different analysis, including Fourier transform infrared (FT-IR), X-ray diffraction (XRD), inductively coupled plasma (ICP), scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM) thermal gravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET). All these analysis revealed that during coating of Fe3O4@Sh using copper salt (II), synchronized redox sorption of CuII to CuI occurs at the same time as the oxidation of Fe3O4 to γFe2O3. This magnetic catalyst exhibited excellent catalytic activity for regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles via one pot three-component click reaction of sodium azide, terminal alkynes and benzyl halides in the absence of any reducing agent. High yields, short reaction time, high turnover number and frequency (TON = 3.5 * 105 and TOF = 1.0 * 106 h−1 respectively), easy separation, and efficient recycling of the catalyst are the strengths of the present method.

scholarly journals High Active Co/Mg1-xCex3+O Catalyst: Effects of Metal-Support Promoter Interactions on CO2 Reforming of CH4 Reaction

2021 ◽  
Vol 16 (1) ◽  
pp. 97-110
Author(s):  
Faris A. Jassim Al-Doghachi ◽  
Diyar M. A. Murad ◽  
Huda S. Al-Niaeem ◽  
Salam H. H. Al-Jaberi ◽  
Surahim Mohamad ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co2 Reforming Of Ch4 ◽  
Temperature Programmed

Co/Mg1−XCe3+XO (x = 0, 0.03, 0.07, 0.15; 1 wt% cobalt each) catalysts for the dry reforming of methane (DRM) reaction were prepared using the co-precipitation method with K2CO3 as precipitant. Characterization of the catalysts was achieved by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The role of several reactant and catalyst concentrations, and reaction temperatures (700–900 °C) on the catalytic performance of the DRM reaction was measured in a tubular fixed-bed reactor under atmospheric pressure at various CH4/CO2 concentration ratios (1:1 to 2:1). Using X-ray diffraction, a surface area of 19.2 m2.g−1 was exhibited by the Co/Mg0.85Ce3+0.15O catalyst and MgO phase (average crystallite size of 61.4 nm) was detected on the surface of the catalyst. H2 temperature programmed reaction revealed a reduction of CoO particles to metallic Co0 phase. The catalytic stability of the Co/Mg0.85Ce3+0.15O catalyst was achieved for 200 h on-stream at 900 °C for the 1:1 CH4:CO2 ratio with an H2/CO ratio of 1.0 and a CH4, CO2 conversions of 75% and 86%, respectively. In the present study, the conversion of CH4 was improved (75%–84%) when conducting the experiment at a lower flow of oxygen (1.25%). Finally, the deposition of carbon on the spent catalysts was analyzed using TEM and Temperature programmed oxidation-mass spectroscopy (TPO-MS) following 200 h under an oxygen stream. Better anti-coking activity of the reduced catalyst was observed by both, TEM, and TPO-MS analysis. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Effects of Platinum and Palladium Metals on Ni/Mg1-xZrxO Catalysts in the CO2 Reforming of Methane

2018 ◽  
Vol 13 (2) ◽  
pp. 295 ◽  
Author(s):  
Faris Jasim Abdulridha Al-Doghachi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Coke Formation ◽  
Dry Reforming Of Methane ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Gravimetric Analysis ◽  
Co2 Reforming ◽  
X Ray ◽  
Co2 Reforming Of Methane

Nickel, palladium, and platinum catalysts (1 wt.% each) supported on MgO and MgZrO to prepare Pt,Pd,Ni/Mg1-xZrxO catalysts (where x = 0, 0.03, 0.07, and 0.15), were synthesized by using co-precipitation method with K2CO3 as the precipitant. X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), H2-temperature programmed reduction (H2-TPR), and thermo gravimetric analysis (TGA) were employed to observe the characteristics of the prepared catalysts. The Pt,Pd,Ni/Mg0.85Zr0.15O showed the best activity in dry reforming of methane (DRM) with 99 % and 91 % for CO2 and CH4 conversions, respectively and 1.28 for H2/CO ratio at temperature 900 °C and 1:1 of CH4:CO2 ratio. The stability of Pt,Pd,Ni/Mg0.85Zr0.15O catalyst in the presence and absence of low stream 1.25 % oxygen was investigated. Carbon formation and amount in spent catalysts were examined by TEM and TGA in the presence of stream oxygen. The results showed that the amount of carbon was suppressed and negligible coke formation (less than 3 %) was observed. Several effects were observed with ZrO2 use as a promoter in the catalyst. Firstly, the magnesia cubic phase stabilized. Secondly, thermal stability and support for basicity increased. Thirdly, carbon deposition and the reducibility of Ni2+, Pd2+, and Pt2+ ions decreased. Copyright © 2018 BCREC Group. All rights reservedReceived: 25th October 2017; Revised: 2nd January 2018; Accepted: 18th January 2018; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Al-Doghachi, F.A.J. (2018). Effects of Platinum and Palladium Metals on Ni/Mg1-xZrxO Catalysts in the CO2 Reforming of Methane. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 295-310 (doi:10.9767/bcrec.13.2.1656.295-310) 

Large Scale Preparation of β-AgVO3 Nanowires Using a Novel Sonochemical Route

2008 ◽  
Vol 8 (6) ◽  
pp. 3203-3207 ◽  
Author(s):  
Changjie Mao ◽  
Xingcai Wu ◽  
Jun-Jie Zhu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Lithium Ion Batteries ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Lithium Ion ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

A large number of β-AgVO3 nanowires with diameter of 30–60 nm, and length of 1.5–3 μm have been successfully synthesized by a simple and facile low-temperature sonochemical route. The morphologies and structures of the nanowires were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning transmission electron microscopy (SEM), and thermal gravimetric analysis (TGA). Cyclic voltammetry and charge–discharge experiments were applied to characterize the electrochemical properties of the nanowires as cathode materials for lithium-ion batteries. In the initial discharge and charge process, the as-prepared β-AgVO3 nanowires showed the initial charge and discharge capacities of 69 and 102 (mAh)/g, respectively. It is anticipated that the β-AgVO3 nanostructures are promising cathode candidates in the application of primary lithium-ion batteries.

scholarly journals Development and Characterization of Cellulose/Iron Acetate Nanofibers for Bone Tissue Engineering Applications

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1339
Author(s):  
Hamouda M. Mousa ◽  
Kamal Hany Hussein ◽  
Mostafa M. Sayed ◽  
Mohamed K. Abd El-Rahman ◽  
Heung-Myong Woo
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Photoelectron Spectroscopy ◽  
Cell Attachment ◽  
Future Application ◽  
Apatite Formation ◽  
Gravimetric Analysis ◽  
Engineering Applications ◽  
X Ray

In tissue engineering, design of biomaterial with a micro/nano structure is an essential step to mimic extracellular matrix (ECM) and to enhance biomineralization as well as cell biocompatibility. Composite polymeric nanofiber with iron particles/ions has an important role in biomineralization and collagen synthesis for bone tissue engineering. Herein, we report development of polymeric cellulose acetate (CA) nanofibers (17 wt.%) and traces of iron acetates salt (0.5 wt.%) within a polymeric solution to form electrospinning nanofibers mats with iron nanoparticles for bone tissue engineering applications. The resulting mats were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The resulted morphology indicated that the average diameter of CA decreased after addition of iron from (395 ± 30) to (266 ± 19) nm and had dense fiber distributions that match those of native ECM. Moreover, addition of iron acetate to CA solution resulted in mats that are thermally stable. The initial decomposition temperature was 300 °C of CA/Fe mat > 270 °C of pure CA. Furthermore, a superior apatite formation resulted in a biomineralization test after 3 days of immersion in stimulated environmental condition. In vitro cell culture experiments demonstrated that the CA/Fe mat was biocompatible to human fetal-osteoblast cells (hFOB) with the ability to support the cell attachment and proliferation. These findings suggest that doping traces of iron acetate has a promising role in composite mats designed for bone tissue engineering as simple and economically nanoscale materials. Furthermore, these biomaterials can be used in a potential future application such as drug delivery, cancer treatment, and antibacterial materials.

scholarly journals Three-Dimensional S/CeO2/RGO Composites as Cathode Materials for Lithium–Sulfur Batteries

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1720 ◽  
Author(s):  
Qiuyan Hao ◽  
Guoliang Cui ◽  
Yuan Tian ◽  
Taizhe Tan ◽  
Yongguang Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Reversible Capacity ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Lithium Sulfur Batteries ◽  
3D Composite ◽  
Composition Structure ◽  
Lithium Sulfur

In this paper, the synthesis of the three-dimensional (3D) composite of spherical reduced graphene oxide (RGO) with uniformly distributed CeO2 particles is reported. This synthesis is done via a facile and large-scalable spray-drying process, and the CeO2/RGO materials are hydrothermally compounded with sulfur. The morphology, composition, structure, and electrochemical properties of the 3D S/CeO2/RGO composite are studied using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), Raman spectra and X-ray photoelectron spectroscopy (XPS), etc. The electrochemical performance of the composites as electrodes for lithium–sulfur batteries is evaluated. The S/CeO2/RGO composites deliver a high initial capacity of 1054 mAh g−1, and retain a reversible capacity of 792 mAh g−1 after 200 cycles at 0.1 C. Profiting from the combined effect of CeO2 and RGO, the CeO2/RGO materials effectively inhibit the dissolution of polysulfides, and the coating of spherical RGO improves the structural stability as well as conductivity.

Biocompatibility of Cerium Oxide Films Synthesized by Dual Plasma Deposition

2007 ◽  
Vol 330-332 ◽  
pp. 749-752
Author(s):  
Feng Juan Jing ◽  
Lu Wang ◽  
Y.W. Liu ◽  
J.Y. Cheng ◽  
Yong Xiang Leng ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Photoelectron Spectroscopy ◽  
Plasma Deposition ◽  
Oxide Films ◽  
Rare Earth Oxide ◽  
X Ray Diffraction ◽  
Good Adhesion ◽  
X Ray ◽  
Huvec Cells ◽  
Isotropic Carbon

Cerium oxide films have been fabricated using dual plasma deposition. X-ray diffraction. (XRD) reveals a crystalline phase and X-ray photoelectron spectroscopy (XPS) shows that La exists predominantly in the +4 oxidation state. The activated partial thromboplastin time is longer than that of blood plasma and stainless steel. Furthermore, the numbers of adhered, aggregated and morphologically changed platelets are reduced compared to low-temperature isotropic carbon (LTIC). HUVEC cells exhibit good adhesion and proliferation behavior on cerium oxide films. This study suggests rare earth oxide films are potential blood-contacting biomedical materials.

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