Highly Active and Stable Bimetallic Rhfe/HAP Catalyst for Direct and Non-Thermal Plasma Synergistic Catalysis of N2o Decomposition

The motivation for this paper is to further improve the efficiency of N₂O decomposition on bimetallic catalysts which often possess a superior performance than their monometallic counterparts by non-thermal plasma (NTP) synergistic effect. The N₂O decomposition in the presence of hydroxylapiatite (HAP) supported Rh and Fe monometallic and bimetallic catalysts have been investigated. Also NTP synergistic effect has been inspected. The HAP is prepared at different pH values and the Rh/Fe supported catalysts synthesized by impregnation method. The research illustrates that basic sites are in favor of N₂O decomposition. The bimetallic catalyst RhFe/HAP-11 possesses a superior performance compared to its monometallic counterparts. The T₅₀ values of RhFe/HAP-11 is 285ºC and that of the catalyst with hydrogen pretreatment is 207ºC which is the minimum value as far as we know. When plasma is applied to synergistic catalysis, N₂O conversion on RhFe/HAP-11 at 200ºC increases a lot from 35.7% to 84.1% (one-stage mode) and 81.0% (two-stage mode). And the N₂O conversion increases with the rise of plasma discharge power. The results of the catalyst characterization by XPS, SEM, TEM demonstrated that metal particles on the catalyst without pretreatment are in oxidation state and uniformly dispersing, zero-valence metal on catalyst make the N₂O conversion higher. TG curve and continue test illustrate that the catalyst has ideal thermal stability. All the results show that with RhFe/HAP-11 catalyst and non-thermal plasma synergistic catalysis in the N₂O decomposition, ideal conversion can be gotten in the low temperature range.