Analysis of SCR properties of metal oxide catalysts enhanced by non-thermal plasma - Promoting effect of NH3

Abstract

Traditional methods of preparing catalysts suffer from suboptimal selectivity and activity. Consequently, this study investigated the modification of iron–cerium (Fe–Ce) oxide catalysts through a non-thermal plasma technique to enhance their reaction activity. Ammonia (NH₃), utilized as the reaction atmosphere during plasma treatment, plays a crucial role in enhancing denitration performance. Among them, the catalyst displays the best low-temperature SCR activity in 40 % NH₃/N₂ atmosphere. The initial NO conversion rate of NH₃-SCR of Fe/Al₂O₃ catalyst at 330 °C can reach 95.3 % when the NO input was 1000ppm. The characterization results indicated that the addition of NH₃ transformed the active components of the catalyst from Fe₂O₃ to Fe₃O₄ and Fe₄ N, and increased the nitrogen content in the catalyst, thus enhancing the synergistic effect and redox capacity of the catalysts, which was conducive to the adsorption and activation of the reactants. Additionally, the dispersion of catalyst and the interaction strength between active component and support were enhanced. In addition, the sulfur resistance of the catalyst doped with Ce was significantly improved. This study presented catalysts modified using a non-thermal plasma technique, effectively enhancing catalyst dispersion and increase the content of N, providing new insights for advanced catalyst modification.