Sol-gel synthesis of a series of first row d-block ferrites: Via the epoxide addition method

Ferrite spinels of the late first-row d-block metals were synthesized in a uniform manner via the epoxide addition method. Cobalt, nickel, copper and zinc ferrites were generated under mild and favorable conditions and analyzed for trends in the series. All ferrites follow a pronounced trend in particle size and are generally identical beyond the identity of the cation. A crystalline copper ferrite phase is not obtainable under identical annealing procedures, but is obtained at high temperature and amorphous material is obtainable for catalytic testing and comparison within the set. The results indicate that while the epoxide addition method is a powerful and facile synthetic procedure to obtain metal-oxide aerogels, individual metal properties can complicate its use in catalyst comparisons. With the exception of copper ferrite, the other spinels in the series are ideally suited to functional comparisons and exploration of the catalytic parameter space for these materials. All of these ferrites are high surface area and highly porous materials, with uniform particle size modes ranging from 4-8 nm.