Compositions and methods for the preparation of ZPGM oxidation catalyst systems are disclosed. ZPGM catalyst systems may be employed within catalytic converters under lean hydrocarbon, air to fuel ratio condition to oxidize toxic gases, such as carbon monoxide and other hydrocarbons that may be included in exhaust gas. ZPGM oxidation catalyst systems are completely free of PGM catalyst and may include: a substrate, a washcoat, and an overcoat. Washcoat may include silver as ZPGM catalyst, and carrier material oxides. Similarly, overcoat may include at least one ZPGM catalyst, carrier material oxides and OSMs. Overcoat of the disclosed ZPGM catalyst system may include copper and cerium as ZPGM catalysts. Suitable known in the art chemical techniques, deposition methods and treatment systems may be employed in order to form the disclosed ZPGM catalyst systems. ZPGM catalyst systems may include high surface area, low conversion temperature catalysts that may exhibit high efficiency in the conversion of exhaust gases.