Porous　metals　with　a　cellular　architecture　have　attracted　considerable　attention　for　a　diverse　range　of　applications.　Extensive　efforts　have　been　devoted　to　exploring　cost-effective　ways　to　create　porous　metals.　Here　we　propose　a　novel　approach　for　the　fabrication　of　micron　porous　Ni　metals　through　a　redox　process　in　a　CH4-O2　gas　mixture　at　750　°C.　The　multiple　redox　cycles　at　high　temperatures　facilitate　a　rapid　reconstruction　of　Ni　atoms,　producing　a　cellular　architecture.　This　process　is　simple　and　clean,　avoiding　the　use　of　precious　metals　and　templates.　The　redox　process　is　applicable　to　the　creation　of　porous　architectures　(from　surface　texturing　to　3D　cellular　structures)　on　a　Ni　sheet　and　a　unique　hierarchical　porous　architecture　on　Ni　foam.　Furthermore,　nanocrystalline　MnO2　is　successfully　coated　on　a　micron　porous　Ni　foam　(MPNF)　to　form　a　supercapacitor　electrode.　The　micron　porous　architectures　of　the　MPNF-MnO2　electrode　enhance　not　only　the　electrochemical　performance　but　also　the　mechanical　integrity　and　robustness,　leading　to　ultrahigh　capacitance　and　excellent　cycling　stability.　More　importantly,　the　strategy　of　micron-sculpturing　of　metals　using　a　redox　process　is　readily　applicable　to　other　metal　systems　for　the　fabrication　of　cellular　metals　and　alloys　for　a　variety　of　applications,　including　catalysis,　energy　storage　and　conversion,　and　chemical　sensing.　©　2017　The　Royal　Society　of　Chemistry.