PREPARATION OF REACTIVE NICKEL-OXIDE BY THE CONTROLLED THERMOLYSIS OFHEXAHYDRATED NICKEL NITRATE

Sample Controlled Thermal Analysis is used to highlight the role of th e experimental pressure on the thermolysis of hexahydrated nickel nitr ate to nickel oxide. At 5 X 10(-2) mbar, dehydration occurs before den itration begins. Formation of an amorphous material occurs, correspond ing to the composition of the monohydrate. At 5 mbar, a basic salt is formed. Both these thermal decompositions occur in the solid state whe reas at 100 mbar melting occurs, The nature of the nickel oxide formed depends strongly on the experimental pressure. Increasing this pressu re increases the temperature of nickel oxide formation. At 5 X 10(-2) mbar an oxide of 80 m(2)g(-1) is obtained whereas at 5 mbar and 100 mb ar no significant surface area accessible to nitrogen is observed.