Variations of bulk powder catalyst material including Cu-Co, Fe-Co, and Co-Mn spinel systems for ZPGM TWC applications are disclosed. The disclosed bulk powder catalyst samples include stoichiometric and nonstoichiometric Cu-Co, Fe-Co, and Co-Mn spinels on Pr 6 O 11 -ZrO 2 support oxide, prepared using incipient wetness method. Activity measurements under isothermal steady state sweep test condition may he performed rich to lean condition. Catalytic activity of bulk powder samples may be compared to analyze the influence that different bimetallic spinel compositions may have on TVVC performance, including ZPGM materials for a plurality of TWC applications. Stoichiometric Cu-Co, Fe-Co, and Co-Mn spinel systems exhibit higher catalytic activity than non-stoichiometric Cu-Co, Fe-Co, and Co-Mn spinel systems. The influence of stoichiometric Cu-Co, Fe-Co, and Co-Mn spinel systems may lead into cost effective manufacturing solutions for ZPGM TWC systems.