YMn2O5 pseudo-brookite compositions with improved thermal stability and catalytic activity as Zero-PGM (ZPGM) catalyst systems for DOC application are disclosed. Testing of YMn2O5 pseudo-brookite catalysts and YMnO3 perovskite catalysts, including variations of calcination temperatures, are performed under DOC light-off (LO) tests at wide range of space velocity to evaluate catalytic performance, especially level of NO oxidation. The presence of YMn2O5 pseudo-brookite oxides in disclosed ZPGM catalyst compositions is analyzed by x-ray diffraction (XRD) analysis. XRD analyses and LO tests confirm that YMn2O5 pseudo-brookite catalysts exhibit higher catalytic activity and significant improved thermal stability when compared to conventional YMnO3 perovskite catalysts.