Fabricating M/Al2O3/cordierite (M = Cr, Mn, Fe, Co, Ni and Cu) monolithic catalysts for ethyl acetate efficient oxidation: Unveiling the role of water vapor and reaction mechanism

•A series of transition metal cordierite-based monolithic catalysts were prepared.•Mn/Al2O3/COR shows excellent ethyl acetate (EA) oxidation activity and water resistance.•Surface oxygen species (Oβ) play vital roles in EA activation and intermediate generation.•Low content water vapor (≤1 vol%) promotes EA activation and ethanol formation.•Water vapor leads to the decline of Oβ and formation of large-size hard coke.