Effect of catalytic activities of mixed nano ferrites of zinc and copper on decomposition kinetics of lanthanum oxalate hydrate

作     者：H.NAYAK H. NAYAK

作者机构：Department of Chemistry Orissa University of Agriculture and TechnologyBhubaneswar 751003(Orissa)India 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2016年第26卷第3期

页      面：767-774页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

主　　题：mixed ferrite spinel valence induction catalyst activity rate constant lanthanum oxalate 

摘      要：Nanostructured zinc-copper mixed ferrite was synthesized using sol-gel method. Different compositions of ferrite, Zn_((1-x))Cu_xFe_2O_4(x=0.0, 0.25, 0.50, 0.75), characterized by XRD, reveal single phase inverse spinel in all the samples. With increasing copper content, the crystallite size increases. The surface morphology of all the samples, studied by SEM, shows porous structure of particles. The prepared samples were also analyzed by FT-IR and TEM. Catalytic activity of the samples was studied on lanthanum oxalate decomposition by *** rate constant k has the highest value with x=0.75 and 5%(mole fraction) of the catalyst and is attributed to high copper content, the mixed sites Cu^(2+)-Fe^+ and/or Cu^+-Fe^(2+) ion pairs besides the one component sites Cu^(2+)-Cu^+, Fe^(3+)-Fe^(2+), as a result of mutual charge interaction. In other words, the increasing activity of mixed oxides is attributed to increase in the content of active sites via creation of new ion pairs. With increasing Zn content, particle size increases. Variation of catalytic activity of ferrite powders is due to the changes of the valence state of catalytically active components of the ferrites, which oxidizes the carbon monoxide released from lanthanum oxalate.