yCeO(2)/Zr-PILC　(y　=　2.5-7.4　wt%)　catalysts　were　prepared　using　an　impregnation　method.　The　physiochemical　properties　of　the　materials　were　investigated　by　means　of　XRD,　BET,　XPS,　H-2-TPR,　NH3-TPD,　and　in　situ　DRIFT　techniques,　and　their　catalytic　activities　were　evaluated　for　the　selective　catalytic　reduction　of　NO　with　ammonia　(NH3-SCR).　The　5CeO(2)/Zr-PILC　sample　showed　a　high　NH3-SCR　activity,　with　the　NO　conversion　being　more　than　80%　in　the　temperature　range　(350-450　degrees　C).　The　Zr-incorporated　support　was　beneficial　for　the　dispersion　of　ceria.　There　was　a　strong　interaction　between　ceria　and　Zr-PILC,　which　led　to　increased　H-2　consumption　and　high-temperature　reduction.　An　appropriate　CeO2　loading　could　generate　the　5CeO(2)/Zr-PILC　catalyst　that　contained　higher　amounts　of　Ce3+　and　the　chemisorbed　oxygen　species　favoring　the　NH3-SCR　reaction.　Moreover,　the　high　acidity　and　strong　NH3　adsorption　ability　of　5CeO(2)/Zr-PILC　were　responsible　for　good　NH3-SCR　performance　in　a　wide　temperature　range.　The　NH3-SCR　reaction　occurred　according　to　both　the　Langmuir-Hinshelwood　(L-H)　and　Eley-Rideal　(E-R)　mechanisms,　with　the　former　being　dominant.