Ammonia　(NH3)　has　been　considered　to　be　a　promising　hydrogen　storage　medium　owing　to　the　carbon-free　features,　easy　liquefaction　storage,　low　transportation　costs,　and　potential　ammonia　production　from　renewable　energy　sources.On-sitehydrogen　production　using　ammonia　decomposition　offers　a　sustainable　and　cost-efficient　solution　for　hydrogen　refuelling　stations,　and　separating　H2from　a　H2-N2mixture　is　a　necessary　step　to　obtain　high-purity　H2(>99.97%).　In　the　scale　of　a　hydrogen　refuelling　station　(∼300　Nm3h−1),　using　pressure-swing　adsorption　(PSA)　is　not　feasible　owing　to　its　low　recovery,　while　using　polymeric　membranes　cannot　meet　the　H2purity　demand.　To　achieve　both　a　high　H2purity　and　high　H2recovery,　we　developed　a　physical-chemical　system　model　of　a　300　Nm3h−1on-siteNH3-fed　hydrogen　refuelling　station　to　optimize　a　H2purification　subsystem,　and　furthermore　predicted　the　system　efficiency　and　economic　feasibility.　We　validated　our　system　model　using　experimental　data,　and　compared　eight　different　scenarios　of　H2purification　subsystems.　The　results　reveal　that　a　NH3-fedon-sitehydrogen　refuelling　station　using　a　“PSA-to-membrane”　subsystem　is　a　feasible　method　of　producing　high-purity　H2with　a　H2recovery　greater　than　95%,　which　is　29%　higher　than　a　system　only　using　PSA.　Correspondingly,　the　system　efficiency　increased　from　59.1%　to　85.37%,　and　the　total　specific　cost　was　reduced　by　22%　to　4.31　€　per　kg.　The　feedstock　cost　accounts　for　74%　of　the　total　specific　cost.　Using　our　optimized　hybrid　H2purification　subsystem,　the　H2production　cost　of　the　NH3-fedon-sitehydrogen　refuelling　station　was　at　least　15%　lower　than　other　carbon-free　routes　(such　as　electrolysis,　solar　thermolysis,　photo-electrolysis,etc.),　and　comparable　to　that　of　a　methane　steam　reforming　system　with　carbon　capture　and　storage.　©　The　Royal　Society　of　Chemistry　2020.