Author: Dipankar Koley
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 138
Book Description
Low Temperature Catalytic Oxidation of Carbon Monoxide Over Silica Supported Palladium Catalysts
Author: Dipankar Koley
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 138
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 138
Book Description
In-situ FTIR Studies on Oxidation of Carbon Monoxide Over Silica Supported Palladium Catalysts
Author: Ekua Okoso-Amaa
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 80
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 80
Book Description
Low-temperature Catalytic Oxidation of Carbon Monoxide Over Palladium Metal, Hydrous Palladium Oxides, and Anhydrous Palladium Oxides
Author: Seung-Hoon Oh
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Stoichiometic oxygen concentration plays an important role during CO oxidation over palladium metal. For 1.0 % CO at 200 °C, Pd metal exhibits 100 % CO conversion with 0.51 % O2 in the feedstream. However, the same Pd powder exhibits only 45 % CO conversion with 0.47 % O2. CO oxidation catalytic enhancements from 5 to 100 % are found for a short time period over the temperature range of 185 to 200 °C. During feedstream bypass, the bicarbonate species dissociate into a hydroxyl group and a carbon dioxide molecule. XPS data indicate that a carbon C 1s peak due to bicarbonate is present during the bypass step. Hydrous palladium oxide (PdO. H2O) exhibits 100 % CO conversion even at room temperature. Existence of lattice water and its reaction with CO/O2 are believed to be the reason for the excellent CO oxidation activity.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Stoichiometic oxygen concentration plays an important role during CO oxidation over palladium metal. For 1.0 % CO at 200 °C, Pd metal exhibits 100 % CO conversion with 0.51 % O2 in the feedstream. However, the same Pd powder exhibits only 45 % CO conversion with 0.47 % O2. CO oxidation catalytic enhancements from 5 to 100 % are found for a short time period over the temperature range of 185 to 200 °C. During feedstream bypass, the bicarbonate species dissociate into a hydroxyl group and a carbon dioxide molecule. XPS data indicate that a carbon C 1s peak due to bicarbonate is present during the bypass step. Hydrous palladium oxide (PdO. H2O) exhibits 100 % CO conversion even at room temperature. Existence of lattice water and its reaction with CO/O2 are believed to be the reason for the excellent CO oxidation activity.
Catalytic Oxidation of Carbon Monoxide at Low Concentrations
Author: Avinash G. Mulay
Publisher:
ISBN:
Category :
Languages : en
Pages : 154
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 154
Book Description
Low Temperature Carbon Monoxide Oxidation Over Gold Supported on Iron Oxide Catalysts
Author: Chien Sze
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 310
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 310
Book Description
Catalysts for the Oxidation of Carbon Monoxide at Low Temperatures
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
Four catalysts (hopcalite, Whetlerite, a supported palladium, and a supported platinum) were tested for efficiency in promoting the oxidation of carbon monoxide (CO). At room temperature and 50% RH, hopcalite has no catalytic capability and platinum has practically none. At room temperature and 15% RH, hopcalite is superior to platinum in catalyzing the oxidation of CO. Hopcalite is more efficient than either of the other three catalysts in the 52 to 66 C (125 to 150 F) temperature range at both humidities. Platinum and palladium are superior to both hopcalite and Whetlerite at both humidities in the 113 to 135 C (235 to 275 F) temperature range. Higher humidity decreases the CO-oxidizing capabilities of hopcalite and Whetlerite but does not do so for platinum and palladium. Whetlerite is in the lower-performing group of catalysts under all except one of the different conditions used in the tests. For the hopcalite, palladium, and platinum catalysts there is a temperature below 135 C (275 F) and above 68 C (155 F) at which CO can be oxidized efficiently.
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
Four catalysts (hopcalite, Whetlerite, a supported palladium, and a supported platinum) were tested for efficiency in promoting the oxidation of carbon monoxide (CO). At room temperature and 50% RH, hopcalite has no catalytic capability and platinum has practically none. At room temperature and 15% RH, hopcalite is superior to platinum in catalyzing the oxidation of CO. Hopcalite is more efficient than either of the other three catalysts in the 52 to 66 C (125 to 150 F) temperature range at both humidities. Platinum and palladium are superior to both hopcalite and Whetlerite at both humidities in the 113 to 135 C (235 to 275 F) temperature range. Higher humidity decreases the CO-oxidizing capabilities of hopcalite and Whetlerite but does not do so for platinum and palladium. Whetlerite is in the lower-performing group of catalysts under all except one of the different conditions used in the tests. For the hopcalite, palladium, and platinum catalysts there is a temperature below 135 C (275 F) and above 68 C (155 F) at which CO can be oxidized efficiently.
Catalytic Oxidation of Carbon Monoxide Over Palladium-copper Nanoalloy Catalysts
Author: Eunjoo Kim
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 52
Book Description
Synthesis and Characterization of Support-modified Nanoparticle-based Catalysts and Mixed Oxide Catalysts for Low Temperature CO Oxidation
Author: Andrew Justin Binder
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 156
Book Description
Heterogeneous catalysts are responsible for billions of dollars of industrial output and have a profound, if often understated, effect on our everyday lives. New catalyst technologies and methods to enhance existing catalysts are essential to meeting consumer demands and overcoming environmental concerns. This dissertation focuses on the development of catalysts for low temperature carbon monoxide oxidation. CO [carbon monoxide] oxidation is often used as a probe reaction to test overall oxidation activity of a given catalyst and is an important reaction in the elimination of toxic pollutants from automotive exhaust streams. The work included here presents three new heterogeneous catalysts developed over the last 4 years in our group. The first type Au/SiO2 [gold/silica] catalyst synthesized using a new method for the deposition of Au nanoparticles onto SiO2 via a nitrogen-containing polymer, C3N4 [carbon nitride]. C3N4-modification of SiO2 allows us to ignore unfavorable electrostatic effects that hinder standard Au deposition onto this support. While removal of the C3N4 is necessary for good CO oxidation, this new method is an improvement over the standard deposition-precipitation procedure for supports with low isoelectric point that enables the successful deposition of Au nanoparticles onto SiO2. The second type includes precious metal catalysts deposited on an “inert” silica support but promoted by the addition of an “active” metal oxide. Here we present a Au/FeOx̳/SiO2 [gold/iron oxide/silica] and a Pd/ZrO2/SiO2 [palladium/zirconia/silica] catalyst which show increased activity and stability effects due to the presence of the metal oxide promoter. They are synthesized by a C3N4-deposition and sol-gel methods, respectively. These catalysts were also tested in simulated automotive exhaust streams. The results show that inhibition effects play a major role in the activity of these catalysts. The third type of catalyst is a mixed oxide catalyst, CuO-Co3O4-CeO2 [copper oxide-cobalt oxide-cerium oxide], developed with the goal of overcoming the inhibition effects seen in the previous precious metal catalysts. The catalyst was synthesized by co-precipitation method and shows exceptional activity for CO oxidation under simulated exhaust conditions. Also noteworthy is the observation that this catalyst also shows a lack of inhibition by a common exhaust component, propene.
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 156
Book Description
Heterogeneous catalysts are responsible for billions of dollars of industrial output and have a profound, if often understated, effect on our everyday lives. New catalyst technologies and methods to enhance existing catalysts are essential to meeting consumer demands and overcoming environmental concerns. This dissertation focuses on the development of catalysts for low temperature carbon monoxide oxidation. CO [carbon monoxide] oxidation is often used as a probe reaction to test overall oxidation activity of a given catalyst and is an important reaction in the elimination of toxic pollutants from automotive exhaust streams. The work included here presents three new heterogeneous catalysts developed over the last 4 years in our group. The first type Au/SiO2 [gold/silica] catalyst synthesized using a new method for the deposition of Au nanoparticles onto SiO2 via a nitrogen-containing polymer, C3N4 [carbon nitride]. C3N4-modification of SiO2 allows us to ignore unfavorable electrostatic effects that hinder standard Au deposition onto this support. While removal of the C3N4 is necessary for good CO oxidation, this new method is an improvement over the standard deposition-precipitation procedure for supports with low isoelectric point that enables the successful deposition of Au nanoparticles onto SiO2. The second type includes precious metal catalysts deposited on an “inert” silica support but promoted by the addition of an “active” metal oxide. Here we present a Au/FeOx̳/SiO2 [gold/iron oxide/silica] and a Pd/ZrO2/SiO2 [palladium/zirconia/silica] catalyst which show increased activity and stability effects due to the presence of the metal oxide promoter. They are synthesized by a C3N4-deposition and sol-gel methods, respectively. These catalysts were also tested in simulated automotive exhaust streams. The results show that inhibition effects play a major role in the activity of these catalysts. The third type of catalyst is a mixed oxide catalyst, CuO-Co3O4-CeO2 [copper oxide-cobalt oxide-cerium oxide], developed with the goal of overcoming the inhibition effects seen in the previous precious metal catalysts. The catalyst was synthesized by co-precipitation method and shows exceptional activity for CO oxidation under simulated exhaust conditions. Also noteworthy is the observation that this catalyst also shows a lack of inhibition by a common exhaust component, propene.
The Activation of Catalysts
Author: Willard Alexander Whitesell
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 24
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 24
Book Description
Oxidation of Carbon Monoxide Over Ceria and Alumina Supported Palladium Catalysts
Author: John Gary Davis
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 102
Book Description
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 102
Book Description