Synthesis process and efficient NH3-SCR performance of alkali/alkaline earth metal-rich Chlorella@Mn catalyst
Hengheng Liu, Fengyu Gao, Songjin Ko, Ning Luo, Xiaolong Tang, Honghong Yi, Yuansong Zhou
Abstract
Low-temperature NH 3 -SCR denitrification catalyst was prepared by biological method using Chlorella cells. In this process, Chlorella cells adsorbed Mn 2+ in manganous solution were centrifuged, dried and calcined to obtain the Chlorella@Mn catalyst, the adsorption process involved electrostatic interaction , complexation/chelation and ion exchange mechanisms. Compared with the pure MnOx catalyst, Chlorella@Mn catalyst contains 2.77% alkali/alkaline earth metals (K, Na, Ca, Mg), but still has higher NOx conversion , N 2 selectivity and anti-H 2 O poisoning, with NOx conversion close to 100% at 100–225 ℃. Chlorella@Mn catalyst surface possesses more acidic species, K, Na, Mg on the surface mainly exist in the form of K 2 SO 4 , NaPO 3 and MgSiO 3 , respectively, Ca mainly exists as amorphous Ca x Mn y O z , and the presence of Ca can inhibit the over-oxidation of NO. Biological methods have more advantages such as simple process and low cost, this study will provide some reference for the preparation of novel denitrification catalysts by biological methods.