Silver nitrate hexamethylenetetramine [Ag(NO3)·N4(CH2)6] coordination compound has been prepared via aqueous route and characterized by chemical analysis, XRD and electron microscopy. Decomposition of [Ag(NO3)·N4(CH2)6] under hydrogen and under inert has been studied by thermal analysis and mass spectrometry. Thermal decomposition of [Ag(NO3)·N4(CH2)6] proceeds in the range 200–250°C as a self-propagating rapid redox process accompanied with the release of multiple gases. The decomposition leads to formation of sponge-like silver having hierarchical open pore system with pore size spanning from 10µm to 10nm. The as-obtained silver sponges exhibited favorable activity toward H2O2 electrochemical reduction, making them potentially interesting as non-enzyme hydrogen peroxide sensors.