Insights into deNOx processing over Ce-modified Cu-BTC catalysts for the CO-SCR reaction at low temperature by in situ DRIFTS

Abstract

Low temperature selective catalytic reduction of NOx (mainly NO and NO2) with CO technology (CO-SCR) is deemed to be a valid and economical solution for NOx abatement in the flue gas. (2NO + 2CO → N2 + 2CO2, 2NO2 + 4CO → N2 + 4CO2). As a burgeoning class of porous hybrid inorganic-organic crystals, Metal-organic frameworks (MOFs) represent great application prospects in the area of catalysis, whereas they were employed in CO-SCR system are scarcely reported. In this work, Cu-BTC and Ce-Cu-BTC catalysts with octahedron shape were synthesized by solvothermal method. The catalytic properties were assessed for selective catalytic reduction of NO with CO (CO-SCR). TGA, XRD, SEM, FT-IR, XPS as well as in situ DRIFTS technologies, are performed to examine the physical and chemical properties of samples. The results demonstrated that the adsorption forms of NO on the catalysts are monodentate nitrites, chelating bidentate nitrates, bridging bidentate nitrates, trans-N2O22− and NO− species. Whereas the adsorption forms of CO are hydrogen carbonate, carbonate species and carbonyl. They all act as intermediates to generate N2 and CO2. The possible reaction mechanism about CO-SCR is discussed.