In　solid　oxide　fuel　cell　(SOFC)　stacks,　the　volatile　boron　species　present　in　the　sealing　glass　often　react　with　the　lanthanum-containing　cathode,　degrading　the　activity　of　the　cathode　(this　phenomenon　is　known　as　boron　poisoning).　In　this　work,　we　report　that　this　detrimental　reaction　can　be　effectively　reduced　by　doping　bismuth-containing　borosilicate　sealing　glass-ceramic　with　a　niobium　dopant.　The　addition　of　Nb2O5　not　only　condenses　the　[SiO4]　structural　units　in　the　glass　network,　but　also　promotes　the　conversion　of　[BO3]　to　[BO4].　Moreover,　the　Nb2O5　dopant　enhances　the　formation　of　boron-containing　phases　(Ca3B2O6　and　CaB2Si2O8),　which　significantly　reduces　the　volatility　of　boron　compounds　in　the　sealing　glass,　suppressing　the　formation　of　LaBO3　in　the　reaction　couple　between　the　glass　and　the　cathode.　The　reported　results　provide　a　new　approach　to　solve　the　problem　of　boron　poisoning.　©　2016　Elsevier　B.V.　All　rights　reserved.