Preliminary work has been conducted with the Pt/Co/silica and Pt/Co/carbon
systems [45]. In the former case, CPA was impregnated at pH 3 onto Co3O4 (PZC 9)
and at the same pH onto a physical mixture of Co3O4 and silica of equivalent exposed
areas. TPR experiments comparing CPA on silica, pure Co3O4, CPA-impregnated