Metallic Nickel Phase Research Articles

E.s.r. study of zeolites containing transition metals and their hydrodesulphurizing activity

The hydrodesulphurizing activity of type Y zeolites modified with cobalt, nickel, molybdenum, zinc and copper is studied towards the reaction hydrogenolysis of diethylsulphide. The state of the metal components in the oxidized, reduced and sulphided forms of molybdenum-, cobalt- and nickel-containing zeolites is studied by means of e.s.r. spectroscopy. Sulphidation of the samples leads to a decrease in the Mo(V) content, to reduction of Co(II) and to an increase in dispersity of the metallic nickel phase. It is shown that efficient catalysts for hydrodesulphurization are obtained not only by the simultaneous use of cobalt and molybdenum as active components, but also by the separate use of cobalt or nickel.

A study of aluminum-nickel-molybdenum zeolite catalysts by ESR methods

1. ESR methods have been used to study the processes involved in the reduction of aluminum-nickel-molybdenum catalysts, some with and some without added zeolite. 2. On the basis of molybdenum(V) thermograms obtained here it has been concluded that at least two types of molybdenum compounds are present in these catalysts. 3. The addition of partially dealuminized zeolite affects the reduction of the hydrogenating component of the catalyst. 4. A finely dispersed metallic nickel phase is formed during reduction of the catalyst. The ferromagnetic resonance spectrum of this nickel is discussed.