Catalytic reduction of nitric oxide with various hydrocarbons

Ault, J. W.; Ayen, Richard J.

doi:10.1002/aic.690170207

Cited by 18 publications

(5 citation statements)

References 10 publications

(5 reference statements)

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“…The apparent activation energies were similar to those found in the nitric oxidelethane reaction over the same catalyst (4) and to the nitric oxide/propane (14,15) and nitric oxide/propylene (16) reactions over various catalysts. In the propane reaction (15) over bismuth phosphomolybdate, the activation energy was 92 kJ mol-' for nitrogen formation and 55 kJ mol-' for nitrous oxide while the corresponding values in the present work were 69 and 30 kJ mol-'.…”

Section: Discussionsupporting

confidence: 60%

Nitric oxide and oxygen reactions with 1-butene over manganese(III) oxide

Ross¹,

Fairbridge²

1983

Can. J. Chem.

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Reactions of 1-butene with nitric oxide from 623 to 723 K and with oxygen from 433 to 573 K have been studied in a differential flow system over manganese(III) oxide. Nitrous oxide was formed in the reaction of the hydrocarbon with nitric oxide along with products of complete combustion. The apparent activation energies were respectively 69 ± 4, 78 ± 4, and 30 ± 4 kJ mol−1 for nitrogen, carbon dioxide, and nitrous oxide reaction rates. The corresponding pre-exponential factors were 1.72 × 10−1 and 1.16 mol0.5 L−0.5 m2 g−1, and 1.99 × 10−2 mol−0.35 L0.35 m2 g−1. In the reaction with oxygen, apparent activation energies of 183 ± 4, 523 to 503 K, and 88 ± 4 kJ mol−1, 503 to 433 K, were determined with pre-exponential factors 1.74 × 1015 and 2.94 × 105 mol0.3 m−2 g−1. During catalysis the oxide underwent a partial phase change from α to γ in both reactions. Additionally, nitrate species were present on the surface after oxidation with nitric oxide. Kinetic expressions have been derived and mechanisms proposed for both reactions which may occur in emission control systems requiring the removal of NOx and unburned hydrocarbons.

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Section: Discussionsupporting

confidence: 60%

Nitric oxide and oxygen reactions with 1-butene over manganese(III) oxide

Ross¹,

Fairbridge²

1983

Can. J. Chem.

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“…Although we are dealing here with only one formulation of a catalyst which has been prepared in a large number of variations having different activity and stability properties (e.g., Beres et al, 1969;Levy, 1968; Peacock et al, 1969a,b), the deficiencies appear too large to be made up. For the copper chromite catalyst, Ault and Ayen (1971) correlate NO conversion with propane by the following…”

Section: Discussionmentioning

confidence: 99%

“…The catalyst is generally less active than copper chromites previously studied, and selectivity for nitrogen formation is obtained only above 600°C.^X considerable amount of work has been devoted to the catalytic reduction of nitric oxide with H2, CO, and various hydrocarbons in conjunction with emission control research, since the direct catalytic decomposition of NO to nitrogen and oxygen is not feasible (Sourirajan and Blumenthal, 1961;Shelef et al, 1969). Noble metals, the oxides of copper and iron, and copper chromite have shown promise (Shelef and Kummer, 1971;Ault and Ayen, 1971), and Ault and Ayen (1971) have obtained quite encouraging results with barium-…”

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confidence: 99%

Bismuth Molybdate Catalysis of Nitric Oxide-Propane Reaction

Stelly¹,

Butt²

1972

Product R&D

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Data are presented for the activity of bismuth phosphomolybdate for reduction of nitric oxide by propane. The catalyst is generally less active than copper chromites previously studied, and selectivity for nitrogen formation is obtained only above 600°C.A considerable amount of work has been devoted to the catalytic reduction of nitric oxide with Hz, CO, and various hydrocarbons in conjunction with emission control research, since the direct catalytic decomposition of NO to nitrogen and oxygen is not feasible (Sourirajan and Blumenthal, 1961; Shelef e t al., 1969). Noble metals, the oxides of copper and iron, and copper chromite have shown promise (Shelef and Kummer, 1971; Xult and Ayen, 1971), and Ault and Ayen (19il) have obtained quite encouraging results with bariumpromoted copper chromite catalysts.There are some notable chemical similarities between the species involved in these reactions and those involved in catalytic ammonoxidation reactions; yet, there have been no studies of the possible effectiveness of ammonoxidation catalysts in the promotion of KO-hydrocarbon reactions. This report gives a summary of results obtained for the reaction of NO with propane, catalyzed by bismuth phosphomolybdate. ExperimentalA conventional fixed-bed flow reactor system was employed in which a feed mixture of N O and C3H8 in helium at 1 a t m total pressure was passed through the bed of catalyst. A fixed feed composition of 5.3 mol 7 0 NO, 1.3 mol % C3H8, and the remainder helium u a s used in these experiments. Space velocities of 6.94 X IO3 and 6.71 X lo4 g catalyst/g mol KO ( W / F N o ) were employed, corresponding to residence times of 0.47 and 5.24 see in the reactor. Two reactors were used for the two space velocity values: the first 0.5 in. diameter and 1 in. long with 3.10 grams of 35 mesh catalyst and a total feed flow of 226 em3 (SC)/min, the second 0.5 >( 7 in with 15.02 grams of 35 mesh catalyst and a total feed flow of 100 em3 (SC)/min. Reactor wall temperature was controlled to *l.O°C by a n external furnace, and reactor temperatures were measured by two iron-constantan thermocouples located on the axis of the catalyst bed a t and 2/3 of the bed length.Total pressures were measured a t various points in the system both upstream and downstream of the reactor, and flow rates were determined by capillary meters for individual feed streams and by a soap film meter for total reactor effluent. Analysis of reaction mixtures was by gas chromatography following the method of Ault and Ayen (1971). MaterialsThe helium used in the reactor and analytical systems was 99.95 mol yo and was dried to equilibrium a t D r y Ice tem-'To whom correspondence should be addressed. perature before use. Instrument grade propane (99.5 mol %) and nitric oxide (99.0 mol %) were supplied by the Matheson Co. The major impurity in these gases was water vapor present in concentrations below the quantitative detection level of the analytical method.The bismuth phosphomolybdate catalyst was prepared according to the procedure of Veach et a...

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“…Olefins generally show a higher activity than alkanes: propene for instance has been found more reactive than propane. Some exceptions should be quoted, ethylene having been found less reactive than CH4 in NO reduction at stoichiometry [98].…”

Section: Reduction Of No By H2 and Hydrocarbonsmentioning

confidence: 99%

Chapter 8 The role of cerium-based oxides used as oxygen storage materials in DeNOx catalysis

Courtois

Bion

Marécot

et al. 2007

Studies in Surface Science and Catalysis

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Materials with high "Oxygen Storage Capacity" (OSC) are now widely used in automotive converter catalysts. There are mainly composed of Ce-based oxides (CeZrOx, CeZrPrOx, ...) having both multiple cationic valencies and oxygen vacancies. These properties allow the catalyst to store active O species (O 2-, superoxide, ...) in O2 excess and to release them when the O2 concentration in gas phase decreases or becomes nil. After having briefly examined the main properties of these OSC materials and the methods employed for their characterization, their impact in automotive catalysis will be reviewed, with a special insight in DeNOx catalysis: (i) in three-way catalysis (TWC) (ii) in automotive catalysis under lean conditions (lean-burn spark ignition engine and Diesel).

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Catalytic reduction of nitric oxide with various hydrocarbons

Cited by 18 publications

References 10 publications

Nitric oxide and oxygen reactions with 1-butene over manganese(III) oxide

Nitric oxide and oxygen reactions with 1-butene over manganese(III) oxide

Bismuth Molybdate Catalysis of Nitric Oxide-Propane Reaction

Chapter 8 The role of cerium-based oxides used as oxygen storage materials in DeNOx catalysis

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