Hierarchically porous Mn3O4 has been synthesized via a facile solution combustion synthesis using Mn(NO3)(2) . 4H(2)O as an oxidizer and ethylene glycolc (EG) as a fuel. The thermal analysis indicated that the combustion reaction can be initiated at a low temperature (126-140 degrees C). The obtained Mn3O4 appeared as a hierarchical network with well-connected poroes. At room temperature, the porous Mn3O4 was found to be highly effective for catalytic degradation of methyl orange (MO) in the presence of acid.