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Indexed by:期刊论文

Date of Publication:2013-05-07

Journal:ENVIRONMENTAL SCIENCE & TECHNOLOGY

Included Journals:SCIE、EI、PubMed、PKU、ISTIC、Scopus

Volume:47

Issue:9

Page Number:4528-4535

ISSN No.:0013-936X

Abstract:The mechanism of selective catalytic reduction of NO by propene (C3H6-SCR) over, the Cu/Ti0.7Zr0.3O2 catalyst was studied by in situ Fourier transform infrared (FTIR) spectroscopy and density functional theory (DFT) calculations. Especially, the formation and transformation of cyanide (-CN species) during the reaction was discussed. According to FTIR results, the excellent performance of the Cu/Ti0.7Zr0.3O2 catalyst in C3H6-SCR was attributed to the coexistence of two parallel pathways to produce N-2 by the isocyanate (-NCO species) and -CN species intermediates. Besides the hydrolysis of the -NCO species, the reaction between the -CN species and nitrates and/or NO2 was also a crucial pathway for the NO reduction. On the basis of the DFT calculations on the energy of possible intermediates and transition states at the B3LYP/6-311 G (d, p) level of theory, the reaction channel of -CN species in the SCR reaction was identified and the role of -CN species as a crucial intermediate to generate N-2 was also confirmed from the thermodynamics view. In combination of the FTIR and DFT results, a modified mechanism with two parallel pathways to produce N-2 by the reaction of -NCO and -CN species over the Cu/Ti0.7Zr0.3O2 catalyst was proposed.