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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