The catalytic chemistry of HCN + NO2 over Na- and Ba-Y,FAU: an in situ FTIR and TPD/TPR study.
The adsorption of HCN and the reaction of HCN with NO(2) over Na-, and Ba-Y,FAU zeolite catalysts were investigated using in situ FTIR and TPD/TPR spectroscopies. Both catalysts adsorb HCN molecularly at room temperature, and the strength of adsorption is higher over Ba-Y than Na-Y. Over Na-Y, the reaction between HCN and NO(2) is slow at 473 K. On Ba-Y, HCN reacts readily with NO(2) at 473K, forming N(2), CO, CO(2), HNCO, NO, N(2)O, and C(2)N(2). The results of this investigation suggest that initial step in the HCN + NO(2) reaction over these catalysts is the hydrogen abstraction from HCN, and the formation of ionic CN- and NC- species. The formation of N(2) can proceed directly from these ionic species upon their interaction with NO+. Alternatively, these cyanide species can be oxidized to isocyanates which then can be further transformed to N(2), N(2)O and CO(x) in their subsequent reaction with NO(x).
Szanyi
János
J
Chemical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-93, Richland, WA 99352, USA. janos.szanyi@pnl.gov
Kwak
Ja Hun
JH
Peden
Charles H F
CH
D000327:Adsorption; D001464:Barium / Q000737:chemistry*; D002384:Catalysis; D006856:Hydrogen Cyanide / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012964:Sodium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D017641:Zeolites / Q000737:chemistry*
D009589:Nitrogen Oxides; D017641:Zeolites; D001464:Barium; D006856:Hydrogen Cyanide; D012964:Sodium