GENERATION OF FINELY-DIVIDED NICKEL PARTICLES IN A PROTECTIVE MEDIUM AND THEIR USE AS HIGH-ACTIVITY CATALYSTS

In this technique, a relatively unreactive substance is transformed into a catalytically-active one within a protective environment. In this illustrative case, nickel formate was dissolved in a solution of poly(ethylene oxide) (PEO) in ethylene glycol, and then thermally decomposed in-situ to form finely-divided nickel particles. The mixture was dried, thereby protecting the nickel by encapsulating it in the polymer matrix. The distribution and the dispersity of nickel particles were investigated by electron microscopy. Upon adding portions of the catalyst-containing polymer to a reaction medium, the protective polymer dissolves, which releases the nickel particles and permits them to catalyze the reaction. In this particular case, the Ni-PEO sample was evaluated for the hydrogenation of an olefin, and found to be a highly efficient catalyst.