Selective catalytic reduction of NOx with NH3 over iron-cerium mixed oxide catalyst prepared by different methods

BACKGROUND Nitrogen oxide (NOx) is one of the important atmospheric pollutants, causing damage to the environment and the human body. Currently, selective catalytic reduction (SCR) technology is the main denitration method, and SCR catalyst is the key to this technology. Iron (Fe)-based catalysts have recently been widely studied because of their low cost and good catalytic effect on medium and low temperature effects. In this article, iron-cerium mixed oxide (FeOx-CeO2) catalysts were prepared by five common preparation methods, and their physicochemical properties and low temperature NH3-SCR catalytic activity were studied. RESULTS The results show that the preparation method has a certain influence on the catalytic performance [activity and nitrogen (N-2) selectivity] of the catalyst. The order of activity is microemulsion method (MM) approximate to sol-gel (SG) method > coprecipitation method > hydrothermal synthesis method > solid-phase mixing (SPM) method. CONCLUSION This result is related to the specific surface area of the catalyst, the microstructure, the valence distribution of the elements, the redox ability and the surface acidic sites. It is worth noting that the activity of the catalyst prepared by the SG method is good, but the selectivity of N-2 is poor, which is related to the oxidizing ability of the catalyst. The catalyst prepared by the MM has moderate oxidizing ability and large specific surface area, provides abundant acidic sites and has excellent catalytic performance. (c) 2019 Society of Chemical Industry