On the different roles of NCO and CN in propene-SCR over silver/alumina
Journal article, 2008

Silver/alumina is one of the most promising catalyst materials for HC-SCR. The reaction mechanism remains incompletely understood, however. Isocyanate species (–NCO) and cyanide species (–CN), important intermediates in the reaction path in HC-SCR, were investigated by gas-phase FTIR and DRIFT spectroscopy in step-response experiments. In accordance with the literature, the corresponding gas-phase species, HNCO and HCN, were always detected at the same time at the different steps of the experiment; however, the accumulation and consumption of surface –NCO and –CN species did not show a similar correlation. Consequently, in conflict with the literature, we propose two parallel, independent reaction pathways for –NCO and –CN species. In one of these reaction pathways, surface nitrates react with C-containing surface species either directly to –NCO or via R–NO2 species. In the other pathway, C-containing surface species react with gas-phase NOx or short-lived N-containing surface species to R–NO species and subsequently to –CN species.

NCO

Reaction mechanism

CN

Propene-SCR

Silver/alumina

NOx reduction

Author

Stefanie Tamm

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Hanna Härelind Ingelsten

Competence Centre for Catalysis (KCK)

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Anders Palmqvist

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Journal of Catalysis

0021-9517 (ISSN) 1090-2694 (eISSN)

Vol. 255 2 304-312

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Transport

Energy

Materials Science

Subject Categories

Chemical Engineering

DOI

10.1016/j.jcat.2008.02.019

More information

Latest update

11/5/2018