Influence of Shaping on Pd and Pt/TiO2 Catalysts in Total Oxidation of VOCs

2011 ◽  
Vol 324 ◽  
pp. 162-165 ◽  
Author(s):  
Tarek Barakat ◽  
Gauthier Finne ◽  
Manuel Franco ◽  
Renaud Cousin ◽  
Jean Marc Giraudon ◽  
...  

The catalytic performance of a commercial TiO2 was investigated towards the total oxidation of toluene. A variety of two titania supports was used in this work, shaped (pellets) and non-shaped (powder) materials. 0.5wt% Pd or Pt were impregnated onto both types of titania supports using the wet impregnation method. A decrease in the surface area of the obtained catalysts was noticed after the catalytic test, although it was still much higher than that of classical titania supports. The catalysts were tested in the total oxidation of toluene, and a major decrease in activity was noticed for Pt impregnated “shaped” supports.

2010 ◽  
Vol 75 (8) ◽  
pp. 1115-1124 ◽  
Author(s):  
Gheorghiţa Mitran ◽  
Ioan-Cezar Marcu ◽  
Adriana Urdă ◽  
Ioan Săndulescu

Vanadium-molybdenum oxides supported on Al2O3, CeO2 and TiO2 were prepared by a ?wet? impregnation method, characterized using DRX, N2 adsorption, UV-Vis spectroscopy, electrical conductivity measurements and tested in the oxidative dehydrogenation of isobutane. The catalytic performance in the oxidative dehydrogenation of isobutane at 400-550?C depended on the nature of support and on the content of VMoO species on the support. The catalysts supported on alumina were more active and selective than those supported on ceria and titania.


Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


2021 ◽  
Author(s):  
Gesha Desy Alisha ◽  
Wega Trisunaryanti ◽  
Akhmad Syoufian

Abstract In this study, natural source Parangtritis beach sand was extracted into mesoporous silica (MS). Synthesis of mesoporous silica (MS) was carried out at sodium silicate: CTAB ratio of 1:0.5 (w/w). Monometallic catalyst was used to improve the performance of the catalyst. The monometallic used was Mo metal, which was synthesized using the wet impregnation method. Catalysts were characterized using FTIR, XRD, Surface Area Analyzer (SAA), SEM-EDX, and TEM. MS has pore diameters and surface area of 2.62 nm and 897.3 m2/g. Mo/MS has pore diameters, surface area, and Mo metal concentration of 2.46 nm, 593 m2/g, and 4.75 %. Catalytic activity and selectivity were evaluated in hydrocracking of waste palm cooking oil at 500, 550, and 600 oC, and catalyst: waste palm cooking oil ratio of 1:100, 1:200, and 1:300. The best catalyst will be tested for reusability 3 times through the hydrocracking process. Mo/MS produces better liquid products and hydrocarbon compounds than MS. The results of the conversion of liquid products analyzed using GCMS. The yield of liquid products obtained in the hydrocracking of waste palm cooking oil using Mo/MS with the optimum temperature and the weight ratio of catalyst: feed at 550oC and 1: 300 was 66.99 wt.% with consists of hydrocarbon compound as 62.79 wt.%. The yield of liquid products obtained in the hydrocracking waste palm cooking oil using the used Mo/MS catalyst in the last run was 80.26 wt.% with consist of hydrocarbon compound as 74.13 wt.%.


Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 994 ◽  
Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3448
Author(s):  
Adrián García ◽  
Rut Sanchis ◽  
Francisco J. Llopis ◽  
Isabel Vázquez ◽  
María Pilar Pico ◽  
...  

γ-Valerolactone (GVL) is a valuable chemical that can be used as a clean additive for automotive fuels. This compound can be produced from biomass-derived compounds. Levulinic acid (LA) is a compound that can be obtained easily from biomass and it can be transformed into GVL by dehydration and hydrogenation using metallic catalysts. In this work, catalysts of Ni (a non-noble metal) supported on a series of natural and low-cost clay-materials have been tested in the transformation of LA into GVL. Catalysts were prepared by a modified wet impregnation method using oxalic acid trying to facilitate a suitable metal dispersion. The supports employed are attapulgite and two sepiolites with different surface areas. Reaction tests have been undertaken using an aqueous medium at moderate reaction temperatures of 120 and 180 °C. Three types of experiments were undertaken: (i) without H2 source, (ii) using formic acid (FA) as hydrogen source and (iii) using Zn in order to transform water in hydrogen through the reaction Zn + H2O → ZnO + H2. The best results have been obtained combining Zn (which plays a double role as a reactant for hydrogen formation and as a catalyst) and Ni/attapulgite. Yields to GVL higher than 98% have been obtained at 180 °C in the best cases. The best catalytic performance has been related to the presence of tiny Ni particles as nickel crystallites larger than 4 nm were not present in the most efficient catalysts.


2016 ◽  
Vol 701 ◽  
pp. 67-72 ◽  
Author(s):  
Mariam Ameen ◽  
Mohammad Tazli Azizan ◽  
Suzana Yusup ◽  
Anita Ramli ◽  
Madiha Yasir ◽  
...  

The studies based on morphological characterization to assess the effects of ultrasound irradiation on synthesis of solid acid catalysts. Three sets of catalyst formulation were synthesized by both wet impregnation method and ultrasound assisted methods with different wt. % of Ni loading on γ-Al2O3. The XRD, BET, TEM and FESEM techniques were used to characterize the nano-particles. Physicochemical characterization revealed that the synthesized catalysts particles using ultrasound irradiation were in nano size range (1-24.5 nm) with equal dispersion of metal oxide, high surface area with increase of metal loading and high phase purity than the catalysts synthesized conventional method. These catalysts were also found in various crystal structures like cubic, monoclinic and tetrahedral. The use of ultrasound irradiation has great significance over the wet impregnation method in relation to the rate of synthesis of nanocatalysts. The high surface area, high thermal stability and small particle size (up to 1 nm) are the basic elements for high activity of solid acid catalysts in hydrocracking and hydrodeoxygenation of various feedstock in petroleum industries.


2010 ◽  
Vol 447-448 ◽  
pp. 770-774 ◽  
Author(s):  
Hakim Lukman ◽  
Zahira Yaakob ◽  
Ismail Manal ◽  
Wan Ramli Wan Daud

Nickel-hydroxyapatite as biomaterial catalysts exhibited high activity and selectivity in glycerol steam reforming. The catalytic steam reforming of glycerol (C3H8O3) for the production of hydrogen is carried out over nickel supported on hydroxyapatite [Ca5(PO4)3(OH)] catalyst at 600 oC with atmospheric pressure and 120 minute time reaction. The catalysts were prepared by mean of wet impregnation method and varied nickel loadings (3, 6, 12 %) on hydroxyapatite. It is found that the 3% wt% Ni/HAP show higher hydrogen production rate over the other nickel loadings on hydroxyapatite, which is correlated with Ni/HAP catalyst surface area measured by BET adsorbtion and morphology of catalysts. Glycerol steam reforming with water-to-glycerol feed ratio 8/1 much more hydrogen production (77-82%) compared feed ratio 4/1. The catalysts were characterised by BET surface area and SEM-EDX techniques.


2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
M. A. Usman ◽  
T. O. Alaje ◽  
V. I. Ekwueme ◽  
E. A. Awe

Highly ordered mesoporous materials are opening the door to new opportunities in catalysis due to their extraordinary intrinsic features. In this study, Nickel was supported on highly ordered mesoporous silica (KIT-6) by the wet impregnation method, and its performance in the hydrogenation of edible vegetable oil was compared with that of Ni/Activated carbon prepared using the same method as well as with unsupported Nickel. The degree of conversion for the 50 : 50 Ni/KIT-6 was 81%, as compared to the 29% obtained with 50 : 50 Ni/Activated carbons. The conversion was found to improve with an increase in mass of supported Nickel on KIT-6 thus 20 : 80 Ni/KIT-6 and 30 : 70 Ni/KIT-6 produced conversions of 71% and 74%, respectively. Key among the benefits of KIT-6 when used as a support material is the very high surface area, open framework of the 3D bicontinuous interconnected channels, and the well-ordered mesopores which bestow on it an advanced mass transfer characteristics.


Cerâmica ◽  
2018 ◽  
Vol 64 (371) ◽  
pp. 436-442 ◽  
Author(s):  
E. O. Moraes Júnior ◽  
J. O. Leite ◽  
A. G. Santos ◽  
M. J. B. Souza ◽  
A. M. Garrido Pedrosa

Abstract La1-xSrxNiO3 (x= 0.0, 0.3 or 0.7) perovskite-type oxides were synthesized using the modified proteic gel method and using collagen as an organic precursor. Catalysts of La1-xSrxNiO3/Al2O3 were obtained using the wet impregnation method. The synthesized catalysts were characterized by X-ray diffraction, surface area and temperature-programmed reduction. The catalysts were evaluated in the partial oxidation reaction of methane, and the levels of selectivity to CO, CO2, H2 and H2O were determined. Among the catalysts studied, the catalyst LaNiO3/Al2O3 had the highest methane conversion level (78%) and higher H2 selectivity (55%).


2021 ◽  
Author(s):  
Nawel Jr ◽  
Thabet Makhlouf ◽  
Gerard Delahay ◽  
Hassib Tounsi

Abstract Copper loaded η-alumina catalysts with different copper contents have been prepared by impregnation/evaporation method. The catalysts were characterized by XRD, FTIR, BET, UV–vis, H2-TPR and evaluated in the selective catalytic reduction of NO by NH3 and in the selective catalytic oxidation of NH3. The characterization techniques showed that the impregnation/evaporation method permits to obtain highly dispersed copper oxide species on the η-alumina surface when low amount of copper is used (1wt. % and 2 wt.%). The wet impregnation method made it possible to reach a well dispersion of the copper species on the surface of the alumina for the low copper contents Cu(1)-Al2O3 and Cu(2)-Al2O3. The latter justifies the similar behavior of Cu(1)-Al2O3) and Cu(2)-Al2O3 in the selective catalytic oxidation of NH3 where these catalysts exhibit a conversion of NH3 to N2 of the order of 100% at T > 500°C.


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