Conformational analysis and comparison between theoretical and experimental vibration spectra for isocyanate species on Ag/Al2O3 catalyst.
Density functional theory (DFT) calculations were performed to study the structure and vibrational frequencies of the intermediate for the isocyanate (NCO) surface species on Ag/Al(2)O(3) catalyst using the GAUSSIAN 98 suite of programs. Thermal decomposition of adsorbed CH(3)NO(2) species leads to the formation of two types of NCO species (NCO on Ag and NCO on Al(2)O(3)) above 298K. In order to investigate the reaction mechanism, we have designed the calculated models (a-g) for the NCO intermediate. Through the analysis of the vibration mode and the vibration frequency of the calculated models (a-g), we conclude that there is an excellent agreement between the calculated vibration spectrum of the model (e) containing the -AgNCO group or model (g) containing the -AlNCO group and the experimental vibration spectrum.
Gao
Hongwei
H
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China.
He
Hong
H
D000537:Aluminum Oxide / Q000737:chemistry*; D002384:Catalysis; D017953:Isocyanates / Q000032:analysis / Q000737:chemistry*; D013058:Mass Spectrometry; D008956:Models, Chemical; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry*; D014732:Vibration
D017953:Isocyanates; D010087:Oxides; D018030:Silver Compounds; C040225:disilver oxide; D000537:Aluminum Oxide