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The transient nature of adsorbates for the reaction of NO with CO over a 4 wt % Rh/Si02 catalyst has been studied by in situ infrared spectroscopy combined with pulse transient techniques. Dynamic behavior of infrared-observable Rh-NO-, Rh-NO+, Rh+(CO)2, and linear and bridged CO reveals that dissociation of Rh-NO-oxidizes Rho to R h ' ; R h ' chemisorbs CO and NO as Rh+(C0)2 and Rh-NO', respectively; and Rh+(CO)* can either undergo reductive agglomeration or react with adsorbed oxygen to produce C02 at 473-523 K. At 573 K, Rh is in the reduced state where linear CO and bridged CO react with the oxygen produced from dissociation of Rh-NO-to produce C02. The catalyst in the reduced surface state is more active for the formation of N20 and C02 products, and the response of N20 formation leads that of COZ formation at temperatures below the light-off temperature. The rapid C02 response during the pulse reaction studies indicates that the reaction can quickly reach steady state at temperatures above 473 K when the reaction conditions are altered.

SUMMARY— 2‐Pentyl furan is identified as a component of the volatile decomposition products of slightly autoxidized soybean and cottonseed oils and those of thermal oxidation of corn oil and hydrogenated cottonseed oil. The flavor threshold of this compound in oil at room temperature is 1 ppm. At concentrations of 1‐10 ppm, it imparts to the oil a characteristic beany odor and flavor reminiscent of those of a reverted soybean oil. Expert organoleptic panels consistently identified a deodorized cottonseed oil containing 5 ppm of 2.pentyl furan as a reverted soybean oil. It is proposed that this compound is formed by autoxidation of linoleic acid.