类水滑石衍生的铁镁铝复合氧化物的制备及与SO_2的反应性  

PREPARATION OF Mg/Al/Fe MIXED OXIDES DERIVED FROM HYDROTALCITES AND THEIR REACTIVITY WITH SO_2

作　　者：王永新[1] 陈大茴[1] 

机构地区：[1]温州医学院,浙江温州325003

出　　处：《硅酸盐学报》2005年第2期191-196,共6页Journal of The Chinese Ceramic Society

摘　　要：以类水滑石为前驱体,制备了一系列铁镁铝复合氧化物,并采用XRD对其结构进行了表征.研究了这类氧化物作为催化剂与SO2反应的活性和机理.结果表明:该材料是由Mg(Fe,Al)O4(少量)、MgO及分散于晶格中的无定型Fe2O3组成,晶粒尺寸微细,Fe2O3组分较为均匀地分散在整个催化剂表面和体相,因此与SO2的反应在相当宽的温度区间(400～700 ℃)有高活性.含Fe3+ 吸附剂上的吸附产物可能存在着类似-Mg-O-SO2-O-Fe-的桥式连接方式.A series of Mg/Al/Fe mixed oxides materials were prepared by using hydrotalcite-like materials as precursor and their crystal structures were characterized by means of XRD. The reactivity and mechanism of the prepared mixed oxides as catalyst with sulfur dioxide were investigated. The results show that the mixed oxides are comprised of Mg(Fe,Al)O4 spinel phase (in small amount), MgO crystal phase and amorphous Fe2O3 which is homogeneously dispersed among the crystal lattice in the surface and bulky phase of the catalyst. High reactivity is observed when the mixed oxides react with dilute SO2 at wide temperature range of 400-700°C. The XRD and FTIR characterization reveal that high reactivity is attributed to the oxidative catalysis role of ferric ions. The saturated products may contain the bridging bonds such as-Mg-O-SO2-O-Fe-because of their over-stoichiometric proportion.

关 键 词：水滑石 复合氧化物 二氧化硫 脱硫 机理 

分 类 号：TB383[一般工业技术—材料科学与工程]