Isocyanate formation in the catalytic reaction of CO + NO on Pd(111): an in situ infrared spectroscopic study at elevated pressures.
The catalytic CO + NO reaction to form CO2, N2, and N2O has been studied on a Pd(111) surface at pressures up to 240 mbar using in situ polarization modulation infrared reflection absorption spectroscopy (PM-IRAS). At 240 mbar, for a pressure ratio of PCO:PNO = 3:2 and under reaction conditions, besides adsorbed CO, the formation of isocyanate (-NCO) was observed. Once produced at 500-625 K, the isocyanate species was stable within the entire temperature range studied (300-625 K). On the other hand, its formation required a total CO + NO pressure of at least 0.6 mbar, illustrating the importance of in situ infrared experiments under high-pressure conditions. The significance of the isocyanate formation for the CO + NO reaction on Pd(111) is discussed.
Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.
Emrah
E
Ozensoy
Christian
C
Hess
D Wayne
DW
Goodman
D000393:Air Pollutants / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry*; D017953:Isocyanates / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D009585:Nitrogen Dioxide / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D011312:Pressure; D011868:Radioisotopes / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods; D001335:Vehicle Emissions
D000393:Air Pollutants; D017953:Isocyanates; D011868:Radioisotopes; D001335:Vehicle Emissions; D002245:Carbon Dioxide; D009569:Nitric Oxide; D010165:Palladium; D002248:Carbon Monoxide; D009584:Nitrogen; D009585:Nitrogen Dioxide