STUDIA UNIVERSITATIS BABEŞ-BOLYAI, CHEMIA, LII, 1, 2007 Dedicated to Professor Ionel Haiduc, President of The Romanian Academy at his 70 th anniversary STUDIES ON SOME OZONE DECOMPOSITION CATALYSTS BASED ON NICKEL OXIDE CRINA DAN 1 , ELISABETH-JEANNE POPOVICI 2 , FLORICA IMRE 1,2 , EMIL INDREA 3 , PETRE MĂRGINEAN 3 AND IOAN SILAGHI-DUMITRESCU 1 ABSTRACT. In order to obtain some efficient ozone decomposition catalysts, nickel oxide powders or alumina-supported nickel oxide samples were prepared and characterised. The catalytic activity of NiO-based catalysts for O3 decomposition, in correlation with their crystalline structure and surface characteristics is investigated. Key words: catalysts; ozone decomposition; nickel oxide; alumina; 1. Introduction Ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers). Moreover, ozone is used in many industrial applications as oxidising agent for example for bleaching, sterilization and wastewaters treatment. For this reason, catalytic ozone decomposition is of practical significance. It proceeds in the presence of precious metals or/and other transition metal oxides deposited onto alumina, and/or titania and/or silica support [1-6]. The catalysts composition and preparation technique as well as the carrier characteristics affect their physico-chemical properties and catalytc activitiy in the process of destruction of ozone in industrial waste gases [7,8]. In order to prepare some efficient ozone decomposition catalysts for environement protection, a complex study has been initiated in our group. In this respect, the preparation and characterisation of some alumina supported manganese, nickel, silver and/or copper based catalysts and their catalytic behaviour in ozone decomposition proccess was investigated. Our previous works showed that manganese oxide supported on gamma alumina is efficient for ozone destruction [9,10]. The present paper refers to the preparation and characterisation of some nickel based catalysts. The goal of the study is to establish the correlation between the catalytic activity and crystalline structure and surface area of catalysts. 1 Faculty of Chemistry and Chemical Engineering “Babes-Bolyai” University, 400028, Cluj-Napoca, 2 "Raluca Ripan” Institute for Research in Chemistry, Fântânele 30, 400294 Cluj-Napoca, 3 “National Institute for R & D for Isotopic and Molecular Technology, 400293 Cluj-Napoca, Romania