Operando FTIR study of reaction pathways of selective catalytic reduction of NOx with decane in the presence of water on iron-exchanged MFI-type zeolite

The reaction mechanism of selective catalytic reduction of NOx with decane on acid and iron-exchanged MFI-type zeolite was investigated by operando FTIR spectroscopy and a special reactor cell enabling the use of water-bearing gas mixtures. Water has a dramatic influence on the reaction pathway. The formation of organic nitro and nitrite compounds does not proceed via chemisorbed states of NOx as observed in SCR with dry gases.