Fundamental studies of active sites and reaction mechanisms for lean NOx reduction over Ag-alumina

Research Project, 2012 – 2018

In recent years the global warming has become a topic of increasing attention. The use of bio fuels constitutes an attractive alternative and e.g. methanol and DME (dimethyl ether) can be produced via gasification of black liquor. The use of such fuels in efficient combustion engines, like the diesel- and lean-burn engines, which operates at oxygen excess, will significantly lower the CO2 emissions. However, emissions of several unwanted substances, like NOx, CO and partly oxidised fuel, will still be significant. The traditional three-way-catalyst can not reduce NOx to a significant extent in excess oxygen. Furthermore, the change of fuel may influence the catalytic activity and selectivity negatively and may also contribute to formation of other harmful substances. This emphasises the need for new catalytic techniques for emission control.

The objective of this project is the lean NOx reduction by methanol (and other relevant future fuels as well as ammonia), the specific structure of the active sites in the silver-alumina system (prepared by the sol-gel route) and formation and reduction of harmful intermediate gas-phase species. The mechanisms for these reactions are likely intimately connected with each other and with the active sites. Detailed understanding of these processes will considerably improve the possibility for enhanced catalytic performance for the lean NOx reduction by methanol and other alternative (bio) fuels.