scholarly journals Preparation, Characterization and CO Oxidation Performance of Ag2O/γ-Al2O3 and (Ag2O+RuO2)/γ-Al2O3 Catalysts

Surfaces ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 251-264
Author(s):  
Antony Ananth ◽  
Rak Hyun Jeong ◽  
Jin-Hyo Boo
Keyword(s):  
Co Oxidation ◽  
Catalyst Support ◽  
Ruthenium Oxide ◽  
Catalytic Performance ◽  
Oxidation Catalyst ◽  
Pore Characteristics ◽  
Good Thermal Stability ◽  
Composite Catalysts ◽  
Highly Active ◽  
Temperature Programmed

This research dealt with the preparation and characterization of silver oxide (SLO) nanomaterials (NMs) and their composite catalysts (i.e., silver and ruthenium oxide (SLORUO)). The prepared materials were tested for their catalytic performance in carbon monoxide (CO) oxidation. Generally, silver in its pure state is not widely used for CO oxidation due to stability and structural issues. However, the usage of subsurface oxygen and oxygen-induced reconstruction could be effective as an oxidation catalyst at a slightly high temperature. The low-temperature reaction of highly active RuO2 (RUO) is a well-known phenomenon. Thus, the possibility of using it with SLO to observe the combined catalytic behavior was investigated. The wet chemically prepared SLO and SLORUO NMs exhibited spherical and rods in spherical aggregate-type surface morphology belonging to cubic and rutile crystalline structures, respectively. The NMs and catalysts (i.e., the NMs on γ-Al2O3 catalyst support at 0.5 and 1.0 wt.% ranges) showed good thermal stability. The dry and wet CO oxidation using RUO and SLO showed concentration-dependent catalytic activity. The RUO, SLO, and SLORUO composites using 0.5 wt.% showed full CO oxidation at 200, 300, and 225 °C, respectively. The reasons for the observed activity of the catalysts are explained based on the pore characteristics, chemical composition, and dispersion using H2 temperature-programmed reduction (TPR) behaviors.

Highly active PdCeOx composite catalysts for low-temperature CO oxidation, prepared by plasma-arc synthesis

2014 ◽  
Vol 147 ◽  
pp. 132-143 ◽  
Author(s):  
R.V. Gulyaev ◽  
E.M. Slavinskaya ◽  
S.A. Novopashin ◽  
D.V. Smovzh ◽  
A.V. Zaikovskii ◽  
...  
Keyword(s):  
Low Temperature ◽  
Co Oxidation ◽  
Plasma Arc ◽  
Composite Catalysts ◽  
Highly Active ◽  
Low Temperature Co Oxidation

scholarly journals CO oxidation over Pt-modified CuO catalysts in the presence of water vapour and SO2

2015 ◽  
Vol 18 (2) ◽  
pp. 187-196
Author(s):  
Tri Nguyen ◽  
Anh Cam Ha ◽  
Loc Cam Luu ◽  
Cuong Tien Hoang ◽  
Thi Thi Yen Trinh ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Water Vapour ◽  
Co Adsorption ◽  
X Ray Diffraction ◽  
Active Centers ◽  
Highly Active ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Adsorption Of Co ◽  
Temperature Programmed

The optimal Pt-modified CuO supported on γ-Al2O3 and γ-Al2O3 + CeO2 catalysts have been prepared. Physico-chemical characteristics of catalysts were investigated and determined by the methods of N2 adsorption (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and hydrogen pulse chemisorption (HPC). The characteristics of carbon monoxide (CO) adsorption on catalysts were defined by the method of infrared spectroscopy (IR) in the range of 4000 – 400 cm-1. The effect of the mixture of water vapour and SO2 on the activity of these catalysts for the CO oxidation was assessed. Reactions were conducted at 200oC and 350oC in the absence and presence of the mixture of water vapour (1.1 mol %) and SO2 (0.0625 mol %). Concentrations of O2 and CO in the gas mixture were 9.2 mol % and 0.5 mol %, respectively. The results showed that in the catalysts there exist highly active centers Cu1+ and Pt2+. On the catalysts the adsorption of CO on Cu2+, Pt2+, CeO2, and γ - Al2O3 centres was observed. Addition of CeO2 led to increase the reductivity, CO adsorption but decrease in specific surface area of catalyst. The result PtCu/CeAl catalyst shown higher active, but lower stability compared to PtCu/Al catalyst. The mixture of water vapour and SO2 showed the reversible poisoning toward the Pt-CuO catalysts at a temperature of 350oC, but irreversible at 200oC

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

scholarly journals γ-Al2O3 supported Pd@CeO2 core@shell nanospheres: salting-out assisted growth and self-assembly, and their catalytic performance in CO oxidation

2015 ◽  
Vol 6 (5) ◽  
pp. 2877-2884 ◽  
Author(s):  
Xiao Wang ◽  
Dapeng Liu ◽  
Junqi Li ◽  
Jiangman Zhen ◽  
Fan Wang ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Self Assembly ◽  
Catalytic Performance ◽  
Core Shell ◽  
Salting Out ◽  
Catalytic Co Oxidation ◽  
Highly Active ◽  
Supported Pd

Highly active Pd@CeO2 core@shell nanospheres with tunable Pd core sizes for catalytic CO oxidation.

Hydrothermal synthesis of manganese oxide nanorods as a highly active support for gold nanoparticles in CO oxidation and their stability at low temperature

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 62732-62738 ◽  
Author(s):  
Yu-Xin Miao ◽  
Li-Hui Ren ◽  
Lei Shi ◽  
Wen-Cui Li
Keyword(s):  
Gold Nanoparticles ◽  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Co Oxidation ◽  
Temperature Programmed Desorption ◽  
Deposition Method ◽  
Highly Active ◽  
Colloidal Deposition ◽  
Oxide Nanorods ◽  
Temperature Programmed

One active Au/MnO2 catalysts were prepared by a colloidal deposition method. The deactivation was studied by temperature programmed desorption of CO2 analysis.

scholarly journals CO2 Reforming of Methane over LaNiO3 Perovskite Supported Catalysts: Influence of Silica Support

2019 ◽  
Vol 14 (3) ◽  
pp. 568 ◽  
Author(s):  
Djamila Sellam ◽  
Kahina Ikkour ◽  
Sadia Dekkar ◽  
Hassiba Messaoudi ◽  
Taous Belaid ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Catalyst Support ◽  
Combustion Method ◽  
Catalytic Performance ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
High Catalytic Activity ◽  
Co2 Reforming ◽  
Auto Combustion ◽  
Temperature Programmed

The study presents the dry reforming of methane using natural Kaolin silica as catalyst support. The silica-supported LaNiO3 perovskite catalysts (20LaNiO3/SiO2 and 40LaNiO3/SiO2) and bulk LaNiO3 catalyst were synthesized by auto-combustion method. The resulting catalysts were characterized by X-ray diffraction (XRD), N2 adsorption - desorption isotherm measurement,  scanning electron microscopy (SEM) and temperature-programmed reduction (TPR). After reduction at 700 °C, they were used as catalysts for the reaction of dry reforming of methane into synthesis gas at atmospheric pressure at 800 °C. The reduced 40LaNiO3/SiO2 exhibited high catalytic activity. This result was attributed to the small Ni metallic particles obtained from the reduced perovskite highly dispersed on the support and the good reducibility. The increase of reduction temperature at 800 °C resulted in a further enhancement of the catalytic performance of 40LaNiO3/SiO2 catalyst. Copyright © 2019 BCREC Group. All rights reserved 

scholarly journals Preferential Oxidation of CO over CoFe2O4 and M/CoFe2O4 (M = Ce, Co, Cu or Zr) Catalysts

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Mehdi Béjaoui ◽  
Abdelhakim Elmhamdi ◽  
Laura Pascual ◽  
Patricia Pérez-Bailac ◽  
Kais Nahdi ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Preferential Oxidation Of Co ◽  
Transmission Electron ◽  
Low Temperature Co Oxidation ◽  
Temperature Programmed ◽  
Diffuse Reflectance Infrared

CoFe2O4 prepared by sol-gel has been examined with respect to its catalytic performance for preferential CO oxidation in a H2-rich stream. In turn, the promoting effects of incorporation of Ce, Co, Cu, and Zr by impregnation on the surface of CoFe2O4 on the process are examined as well. The catalysts have been characterized by N2 adsorption, X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), temperature programmed reduction (TPR), and X-ray photoelectron spectra (XPS), as well as diffuse reflectance infrared DRIFTS under reaction conditions with the aim of establishing structure/activity relationships for the mentioned catalyst/process. It is shown that while the presence of the various metals on CoFe2O4 hinders a low temperature CO oxidation process, it appreciably enhances the activity above 125 °C. This is basically attributed to the surface modifications, i.e. cobalt oxidation, induced in CoFe2O4 upon introduction of the metals. In turn, no methanation activity is observed in any case except for the copper-containing catalyst, in which achievement of reduced states of cobalt appears most favored.

scholarly journals Alumina-supported sub-nanometer Pt10 clusters: amorphization and role of the support material in a highly active CO oxidation catalyst

2017 ◽  
Vol 5 (10) ◽  
pp. 4923-4931 ◽  
Author(s):  
Chunrong Yin ◽  
Fabio R. Negreiros ◽  
Giovanni Barcaro ◽  
Atsushi Beniya ◽  
Luca Sementa ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Oxidation Catalyst ◽  
Support Material ◽  
Highly Active

Bridging the support gap in heterogeneous ultrananocatalysis.

scholarly journals Brownmillerites CaFeO2.5 and SrFeO2.5 as Catalyst Support for CO Oxidation

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6413
Author(s):  
Pierre-Alexis Répécaud ◽  
Monica Ceretti ◽  
Mimoun Aouine ◽  
Céline Delwaulle ◽  
Emmanuel Nonnet ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Catalyst Support ◽  
Catalytic Performance ◽  
Oxidation Catalysis ◽  
Synthesis Methods ◽  
Support Material ◽  
Long Term Stability ◽  
The Impact

The support material can play an important role in oxidation catalysis, notably for CO oxidation. Here, we study two materials of the Brownmillerite family, CaFeO2.5 and SrFeO2.5, as one example of a stoichiometric phase (CaFeO2.5, CFO) and one existing in different modifications (SrFeO2.75, SrFeO2.875 and SrFeO3, SFO). The two materials are synthesized using two synthesis methods, one bottom-up approach via a complexation route and one top-down method (electric arc fusion), allowing to study the impact of the specific surface area on the oxygen mobility and catalytic performance. CO oxidation on 18O-exchanged materials shows that oxygen from SFO participates in the reaction as soon as the reaction starts, while for CFO, this onset takes place 185 °C after reaction onset. This indicates that the structure of the support material has an impact on the catalytic performance. We report here on significant differences in the catalytic activity linked to long-term stability of CFO and SFO, which is an important parameter not only for possible applications, but equally to better understand the mechanism of the catalytic activity itself.

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