Thermal Treatment Effect on Catalytic Activity of Au/TiO2 for CO Oxidation

2014 ◽  
Vol 548-549 ◽  
pp. 254-258
Author(s):  
Asif Mahmood ◽  
Shahid M. Ramay ◽  
Yousef Al-Zeghayer ◽  
Sajjad Haider ◽  
Muhammad Ali Shar ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Thermal Treatment ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Preferential Oxidation ◽  
Reaction Heat ◽  
Oxidation Performance ◽  
Positive Effect

A novel and well-organized study for the synthesis and enhanced catalytic activity of Au/TiO2catalysts has been developed. A momentous improvement in the catalytic activity of Au/TiO2in CO oxidation and preferential oxidation reaction by thermal treatment has been studied. Au/TiO2catalyst (Au (1 wt.%) supported on TiO2) was prepared by conventional deposition-precipitation method with NaOH followed by washing, drying and calcination in air at 400 °C for 4 h. Thermal treatment of Au/TiO2was performed at 450 °C under 0.05 mTorr. The activity of the catalysts has been examined in the reaction of CO oxidation and preferential oxidation (PROX) at 25-250 °C. The catalytic performance was found to be strongly affected by thermal treatment of the prepared catalyst prior to the reaction. Heat treatment after Au deposition has a positive effect on the CO oxidation performance. This is attributed to the introduction of a stronger interaction between the oxide and Au which improves the catalytic activity.

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.

Pt-embedded-CeO2hollow spheres for enhancing CO oxidation performance

2017 ◽  
Vol 1 (9) ◽  
pp. 1754-1763 ◽  
Author(s):  
Ke Wu ◽  
Liang Zhou ◽  
Chun-Jiang Jia ◽  
Ling-Dong Sun ◽  
Chun-Hua Yan
Keyword(s):  
Co Oxidation ◽  
Oxidation Reaction ◽  
Hollow Spheres ◽  
Catalytic Performance ◽  
Co Oxidation Reaction ◽  
Oxidation Performance

Pt-embedded-CeO2hollow spheres are successfully synthesized and show enhanced catalytic performance toward CO oxidation reaction.

scholarly journals Influence of Copper on the Catalytic Activity of Supported Rhodium Catalysts in the Reactions of CO Oxidation and NO Reduction

2017 ◽  
Vol 4 (4) ◽  
pp. 265
Author(s):  
L.A. Petrov ◽  
J. Soria ◽  
R. Cataluna
Keyword(s):  
Catalytic Activity ◽  
Thermal Treatment ◽  
Low Temperature ◽  
Co Oxidation ◽  
No Reduction ◽  
Promoting Effect ◽  
Catalytic Activities ◽  
Cu Catalysts ◽  
Temperature Programmed ◽  
Positive Effect

<p>The catalytic activity of Cu, Rh, and Rh/Cu, catalysts supported on Al<sub>2</sub>O<sub>3</sub>, CeO<sub>2</sub> and CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> in reactions of CO oxidation and NO reduction has been studied in temperature-programmed regime. Addition of Cu to Rh catalysts decreases temperature at which 5 and 50% degree of conversion, while end of reaction temperature is not influenced by presence of Cu. The presence of Cu has positive effect on the activity of Rh containing catalysts in the low temperature region. Cu has noticeable promoting effect mainly for the catalytic activity in the reaction of CO oxidation and in smaller extent for the reaction of NO reduction. Preliminary redox treatment of the catalysts decreases the light off temperature in the reactions of CO oxidation and in NO reduction. Thermal treatment at temperatures up to 973 K does not have sensible effect on the catalytic activities of all studied catalysts. Calcination at 1073 K, however, strongly decreases the catalytic activity of Rh/Cu/CeO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> catalysts.</p>

CO-OXIDATION CATALYZED BY NANOCRYSTALLINE CeO2 PARTICLES WITH DIFFERENT MORPHOLOGIES

2008 ◽  
Vol 15 (01n02) ◽  
pp. 123-131 ◽  
Author(s):  
W. Y. PONG ◽  
H. Y. CHANG ◽  
H. I. CHEN ◽  
J. R. CHANG
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Degree Of Crystallinity ◽  
Precipitation Method ◽  
The Novel ◽  
Morphological Effect ◽  
Co Oxidation Reaction ◽  
Co Conversion ◽  
Structure Morphology

Nanocrystalline cerium oxide ( CeO 2) particles prepared by the novel two-stage precipitation method were used for the catalysis of CO oxidation. Firstly, two shapes, i.e. particulate (P-) and needle-like (N-), CeO 2 nanoparticles were formed via proposed temperature-arranged routes. The crystalline structure, morphology, particle size, and surface area of samples were characterized by using XRD, TEM, HRTEM, and BET techniques. Furthermore, the morphological effect of the CeO 2 samples on the catalytic activity of CO oxidation was investigated. From the experimental results, it indicated that the prepared samples were all nonporous and fcc-structured CeO 2. The CeO 2 particles, as precipitating at 90°C for 5 min and then aging at 90°C, were particulate, whereas they were needle-like by aging at 0°C. The CO oxidation reaction showed that the catalytic activity of N- CeO 2 nanoparticles was higher than that of P- CeO 2, attributing from the exposed higher-energy {100} and {110} facets for N- CeO 2 nanoparticles. Moreover, the calcined samples with higher degree of crystallinity showed further promotion in catalytic activity. It was also worthy to note, that by replacing the CeO 2 catalyst by Pd / CeO 2, a large increase in the CO conversion was found, especially catalyzed by Pd /N- CeO 2.

scholarly journals On the Effects of Doping on the Catalytic Performance of (La,Sr)CoO3. A DFT Study of CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Formation Energy ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Energy Profiles ◽  
High Concentrations ◽  
3D Impurities

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.

SnO2 nano-rods with superior CO oxidation performance

2014 ◽  
Vol 2 (16) ◽  
pp. 5616-5619 ◽  
Author(s):  
Xiang Wang ◽  
Lihong Xiao ◽  
Honggen Peng ◽  
Wenming Liu ◽  
Xianglan Xu
Keyword(s):  
Co Oxidation ◽  
Noble Metal ◽  
Catalytic Performance ◽  
Metal Catalyst ◽  
Noble Metal Catalyst ◽  
Catalytic Behavior ◽  
Oxidation Performance ◽  
Nano Rods

SnO2 with a nano-rod morphology shows a superior catalytic performance over SnO2 with other morphologies for CO oxidation. The SnO2-rods’ catalytic behavior is very similar to that of a noble metal catalyst.

Preparation of cerium doped Cu/MIL-53(Al) catalyst and its catalytic activity in CO oxidation reaction

2017 ◽  
Vol 32 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Haiyan Tan ◽  
Yin Zhou ◽  
Yunfan Yan ◽  
Weibing Hu ◽  
Xinyu Shi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Co Oxidation Reaction

Catalytic Performance of SO2 by Colloidal Gold Supported on Nano γ-Fe2O3

2010 ◽  
Vol 178 ◽  
pp. 65-70 ◽  
Author(s):  
Sheng Rui Xu ◽  
Qin Shuai ◽  
Jin Hua Cheng ◽  
Xiao Ge Wang
Keyword(s):  
Gas Chromatography ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Metal Oxides ◽  
Water Vapour ◽  
Colloidal Gold ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Sulfate Species

A new catalyst of gold supported on nanometal oxide for oxidation of SO2 was developed. Deposition-precipitation method was used to prepare gold-based catalysts. The catalytic activity of the catalysts was evaluated by determining the concentration of SO2 with gas chromatography under reaction temperature from 100 to 700°C. The results showed that there was an enhancement of catalytic activity when gold nanoparticles were dispersed on the surface of nano-metal oxides, furthermore, γ-Fe2O3 showed the highest activity as the support of the colloidal gold supported catalysts among the nanometal oxides including γ-Fe2O3, Fe2O3, ZnO, and Al2O3. It was also found that water vapour in the reaction enhanced the catalytic activity of Au/γ-Fe2O3. The Au/γ-Fe2O3 was characterized by XRD and FTIR methods, which indicated that the gold nanoparticles were dispersed on the γ-Fe2O3 support and sulfate species were formed on the surface of catalysts.

Metal–Organic Framework Derivatives for Improving the Catalytic Activity of the CO Oxidation Reaction

2017 ◽  
Vol 9 (18) ◽  
pp. 15394-15398 ◽  
Author(s):  
Wenlan Ji ◽  
Zhiling Xu ◽  
Pengfei Liu ◽  
Suoying Zhang ◽  
Weiqiang Zhou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Metal Organic Framework ◽  
Co Oxidation Reaction ◽  
Metal Organic ◽  
Organic Framework

scholarly journals Effect of the Preparation Method on the Physicochemical Properties and the CO Oxidation Performance of Nanostructured CeO2/TiO2 Oxides

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 847 ◽  
Author(s):  
Sofia Stefa ◽  
Maria Lykaki ◽  
Dimitrios Fragkoulis ◽  
Vasileios Binas ◽  
Pavlos K. Pandis ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Co Oxidation ◽  
Rational Design ◽  
Mixed Oxides ◽  
Oxygen Storage ◽  
Precipitation Method ◽  
Stöber Method ◽  
X Ray ◽  
Oxidation Performance ◽  
The Stöber Method

Ceria-based mixed oxides have been widely studied in catalysis due to their unique surface and redox properties, with implications in numerous energy- and environmental-related applications. In this regard, the rational design of ceria-based composites by means of advanced synthetic routes has gained particular attention. In the present work, ceria–titania composites were synthesized by four different methods (precipitation, hydrothermal in one and two steps, Stöber) and their effect on the physicochemical characteristics and the CO oxidation performance was investigated. A thorough characterization study, including N2 adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM) and H2 temperature-programmed reduction (H2-TPR) was performed. Ceria–titania samples prepared by the Stöber method, exhibited the optimum CO oxidation performance, followed by samples prepared by the hydrothermal method in one step, whereas the precipitation method led to almost inactive oxides. CeO2/TiO2 samples synthesized by the Stöber method display a rod-like morphology of ceria nanoparticles with a uniform distribution of TiO2, leading to enhanced reducibility and oxygen storage capacity (OSC). A linear relationship was disclosed among the catalytic performance of the samples prepared by different methods and the abundance of reducible oxygen species.

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