Direct　ammonia　solid　oxide　fuel　cells　(NH3-SOFCs)　have　been　triggered　great　attention　due　to　its　high　efficiency　and　＂zero-carbon　emission＂.　The　anode　catalysts　are　remaining　challenging　because　of　the　complex　reaction　processes　of　NH3-SOFCs.　This　work　presents　the　enhanced　electrochemical　performance　by　combining　the　electronic-ionic　conductivity　of　alloys　and　oxygen　conductor,　and　provides　molecular　engineering　insights　into　the　ammonia　oxidation　mechanism.　Fe　atoms　were　partially　substituted　by　Ni　atoms　to　form　spinel　ZnFe2-xNixO4　(ZFNx)　oxides,　which　contributes　to　in-situ　exsolution　of　the　Fe-Ni　alloys　as　active　anodes　of　NH3-SOFCs　under　reducing　atmosphere.　Meanwhile,　the　derived　ZnO　acts　as　an　oxide　carrier　with　the　electrolyte　Gd0.1Ce0.9O1.95　(GDC),　improving　the　dispersion　of　the　alloy　particles　and　providing　a　new　avenue　for　oxygen　ion　conductivity.　The　composite　anode　ZFN0.05-40GDC　ensures　sufficient　electron　and　oxygen　ion　transfer.　Consequently,　the　electrolyte-supported　single　cell　gives　the　optimal　power　output　of　224　mW/cm2　in　NH3,　2.8　times　higher　than　commercial　NiO-40YSZ　one　at　800　degrees　C.　By　distribution　of　relaxation　time　as　well　as　Bode　plots　analysis,　the　preferential　reaction　mechanism　and　rate-determining　step　are　proposed　in　the　anode　reaction.