Ceria based catalysts for low temperature selective catalytic reduction of NO with NH3
Selective catalytic reduction of NO with NH3 (NH3 SCR) is a powerful technique for the abatement of NOx from stationary sources, and the currently used VOx/TiO2 based catalysts are widely applicable for medium temperature conditions but not suitable for NH3 SCR operated at low temperatures. Recently, low temperature NH3 SCR has attracted considerable attention owing to the vast demand in industrial furnaces and its energy conserving feature. During the past years, a great many studies have demonstrated that ceria based catalysts are potential candidates as catalysts for low temperature NH3 SCR. Herein we summarize the recent advances in the application of ceria based catalysts for low temperature NH3 SCR. The review begins with a brief introduction of the general guideline for low temperature NH3 SCR and the interaction between the reactants and CeO2. The different roles of ceria as a pure support/active species, bulk doping component and surface modifier are discussed. As well, the mechanistic investigations (active sites, intermediates, reaction mechanism) and SO2/H2O tolerance are emphasized. Lastly, the perspectives on the opportunities and challenges of ceria based catalysts for low temperature NH3 SCR in future research are presented.