The　poisoning　effects　of　alkali　metals　(K　and　Na)　and　alkaline　earth　metals　(Ca　and　Mg)　on　catalytic　performance　of　the　2Nb4Ce/Zr-PILC　catalyst　for　the　selective　catalytic　reduction　of　NOx　with　NH3　(NH3-SCR)　were　investigated,　and　physicochemical　properties　of　the　catalysts　were　characterized　by　means　of　the　X-ray　diffraction　XRD　(XRD),　Brunner-Emmet-Teller　(BET),　hydrogen　temperature-programmed　reduction　(H-2-TPR),　X-ray　Photoelectron　Spectroscopy　(XPS),　ammonia　temperature-programmed　desorption　(NH3-TPD),　and　in　situ　diffuse　reflectance　infrared　Fourier　transform　spectroscopy　(in　situ　DRIFTS)　techniques.　Doping　of　M　(M　=　K,　Na,　Ca,　and　Mg)　deactivated　the　2Nb4Ce/Zr-PILC　catalyst　according　to　the　sequence　of　0.8　K　＞　0.8　Na　＞　0.8　Ca　＞　0.8　Mg　(M/Ce　molar　ratio　=　0.8).　The　characterization　results　showed　that　the　decreases　in　redox　ability,　NH3　adsorption,　Ce3+/Ce4+　atomic　ratio,　and　amount　of　the　chemisorbed　oxygen　(O-beta)　were　the　important　factors　influencing　catalytic　activities　of　the　alkali　metal-and　alkaline　earth　metal-doped　samples.　Consequently,　compared　with　the　Mg-　and　Ca-doped　samples,　doping　of　K　caused　the　2Nb4Ce/Zr-PILC　sample　to　possess　the　lowest　redox　ability,　NH3　adsorption,　and　amount　of　the　O-beta　species,　which　resulted　in　an　obvious　deactivation　effect.