Surface Technology, 1 7 (1982) 199 - 204 199 ELECTRICAL STUDIES ON V205 CATALYSTS DOPED AND MIXED WITH FOREIGN IONS K. M. ABD EL-SALAAM and A. A. SAID Chemistry Department, Faculty of Science, Assiut University, Assiut (Egypt) (Received May 31, 1982) Summary The electrical conductivity of V2Os catalysts doped and mixed with Fe 3+, Co 3÷ and Ni :÷ ions in the concentration range 0.5 - 70 at.% was studied. Experiments were carried out in air as well as in the presence of 2-propanol in the feed. It has been shown that doping of V2Os with foreign ions in- creases the hole concentration. The calculated AE a values shows that the addition of Ni 2÷ or Fe 3÷ ions increases slightly its p-type character while Co 3÷ ions increase strongly the p-type conductivity of V2Os catalyst. These results were manifested on the addition of 2-propanol. 1. Introduction To understand the behaviour of a catalyst, it is desirable to have an understanding of its chemistry. The most widely used catalyst for oxidation processes is V:Os, pure or mixed with foreign ions [1 - 4]. While a consid- erable amount of work has been carried out on its oxidation mechanism, little definitive work has been done to measure the mechanism of the additive effect through its electrical conductivity properties [5]. It has been shown that the addition of foreign ions to the V:O5 matrix can lead to either an increase or a decrease in the concentration of created defects. Consequently, the addition of foreign ions will affect the catalytic properties of V205. Our goal in the present study is to gain insight into the mechanism by which 3+ Fe , Co 3÷ or Ni 2÷ ions can be incorporated either in small or large amounts in V:Os catalyst. 2. Experimental details V2Os powder doped or mixed with Fe 3., Co 3÷ or Ni 2. ions was prepared by dropwise addition of the nitrate solution of the corresponding ion in appropriate concentrations to ammonium metavanadate under continuous 0376-4583/82/0000-0000/$02.75 © Elsevier Sequoia/Printed in The Netherlands