Insight into the mesoporous FexCe1−xO2−δ catalysts for selective catalytic reduction of NO with NH3: Regulable structure and activity

Abstract A series of mesoporous Fe x Ce 1− x O 2− δ catalysts with high surface area were prepared by a surfactant-assisted method. Thorough characterization of spectroscopic and theoretical approaches sheds new light on relating the regulable structure of the catalysts with activity. Kinetic studies show that the doping of Fe into CeO 2 leads to a decrease of activation energy for the selective catalytic reduction reaction from 52 to 26 kJ mol −1 , which results from the formation of the specific Fe–O–Ce structure. XPS and DFT calculation demonstrate that the formed Fe–O–Ce structure increases the number of Lewis acid sites and enhances the redox properties through the electronic inductive effect between Fe 3+ and Ce 4+ . Importantly, their formation mechanism is related to the Fe content. The lower Fe addition (0  x 2 -like solid solution via a vacancy compensation mechanism, leading to a remarkable increase in oxygen vacancies and thereby in catalytic performance. On the other hand, the higher Fe addition (1 >  x  ⩾ 0.3) creates interstitial Fe 3+ species via a dopant interstitial compensation mechanism. These iron species, with a relatively lower Hirshfeld charge of 0.19, present rich electronic properties, which are favorable for NO oxidation to NO 2 .