La_(2-x)Sr_xCuO_(4-λ)复合氧化物的合成、表征和氨的氧化催化性能的研究

Abstract

合成了X值不同的lA_(2-X)Sr_XCuO_(4-λ)(X=0~1)系列复合氧化物,用Xrd研究了这一系列氧化物的结构,结果表明X在0~0.3之间可形成k_2nIf_4结构单相化合物.用化学分析方法测定了过渡金属Cu的价态及含量,并计算出复合氧化物中的非计量氧数.用TPd,TPr,Tg,XPS,SEM等方法研究了这类复合氧化物的氧化还原性能,所含氧种及表面形态,考察了对nH3氧化的催化活性,并对其催化活性与化学组成及结构的关系进行了讨论.

A series of Sr2+ doped perovskite like oxides La2-xSrxCuO4-λ (x=0 -- 1) were prepared, the structure, lattice parameters, content of Cu3+ , oxygen vacancies created by Sr2+ substitution and composition of these complex oxides were studied by XRD and iodic titration method.The redox ability, active oxygen species and surFace image were evaluated and analyzed with TPD,TG,XPS and SEM measurements.The catalytic activity For ammonia oxidation over these oxides was tested, and the relationship among the catalytic properties, structure, nonstoichiometric oxygen,redox ability and surFace behavior were correlated and some inFormation on the mechanism of ammonia oxidation was obtained.