Organic Chemistry: Current Research
Open Access

Reaction mechanism of low-temperature selective catalytic reduction of NOx over iron and manganese oxides supported on fly ash-derived SBA-15 molecular sieves

11^th Global Experts Meeting on Chemistry And Computational Catalysis

May 18-19, 2018 Singapore

Ge Li, Baodong Wang, Wayne Qiang Xu, Yonglong Li and Qi Sun

National Institute of Clean-and-Low-Carbon Energy, China

Scientific Tracks Abstracts: Organic Chem Curr Res

Abstract :

Fly ash emissions caused by coal combustion have been increasing for many years causing serious environmental pollution. Coal combustion also causes large amounts of NOx to be emitted to the atmosphere and this has caused environmental problems such as acid rain, which cannot be ignored. The denitrification catalyst V2O5/WO3-TiO2 gives good denitrification efficiency at a high temperature but the catalyst gives a poor efficiency at low temperatures (100-300 oC). Therefore, we introduce a new method based on the use of fly ash to control NOx output. We used a two-step alkali hydrothermal method to prepare SBA-15 mesoporous molecular sieves from fly ash obtained from a thermal power plant in Inner Mongolia (China). A series of bimetallic iron and manganese oxides were supported on the fly ash-derived SBA-15 catalyst and excellent NO conversion was found for NH3-SCR at low temperatures. The catalysts were characterized by XRD; XPS; NH3-, O2- and CO2- TPD; H2- TPR, BET analysis, SEM, TEM, and DRIFT spectroscopy. The denitration activity and denitration mechanism over the catalysts is discussed. The mechanisms of NO reduction and N2O formation over Mn/SBA-15 and Fe-Mn/SBA-15 were investigated through in situ DRIFT studies and a transient reaction study. The strong oxidation, low acidity and high basicity of the FeMn/SBA-15 catalyst contributed to a large amount of nitrate being produced during the catalysis. The nitrate decomposed to produce N2O, resulting in a decrease in N2 selectivity. The denitration mechanism of the Fe-Mn/SBA-15 catalyst in the SCR reaction followed Langmuir-Hinshelwood, Eley-Rideal and Mars-van Krevelen mechanisms.

Biography :

Ge Li has pursued her PhD from China University of Geosciences, Beijing. She is currently working at the National Institute of Clean-and-Low-Carbon Energy in China. She is a Senior Engineer. She has done research on the environmental pollution of the atmosphere, water and solid waste. She has published more than 20 papers in reputed journals and applied for more than 10 Chinese invention patents.
Email:lige@nicenergy.com