Catalytic　combustion　is　thought　as　an　efficient　and　economic　pathway　to　remove　volatile　organic　compounds,　and　its　critical　issue　is　the　development　of　high-performance　catalytic　materials.　In　this　work,　we　used　the　in　situ　synthesis　method　to　prepare　the　silicalite-1　(S-1)-supported　Pd　nanoparticles　(NPs).　It　is　found　that　the　as-prepared　catalysts　displayed　a　hexagonal　prism　morphology　and　a　surface　area　of　390-440　m(2)　/g.　The　sample　(0.28Pd/S-1-H)　derived　after　reduction　at　500　degrees　C　in　10　vol%　H-2　showed　the　best　catalytic　activity　for　toluene　combustion　(T-50%　=　180　degrees　C　and　T-90%　=　189　degrees　C　at　a　space　velocity　of　40,000　mL/(g(.)hr),　turnover　frequency　(TOFPd)　at　160　degrees　C　=　3.46　x　10(-3)　sec(-1),　and　specific　reaction　rate　at　160　degrees　C　=　63.8　mu　mol/(g(Pd.sec))),　with　the　apparent　activation　energy　(41　kJ/mol)　obtained　over　the　best　performing　0.28Pd/S-1-H　sample　being　much　lower　than　those　(51　-70　kJ/mol)　obtained　over　the　other　samples　(0.28Pd/S-1-A　derived　from　calcination　at　500　degrees　C　in　air,　0.26Pd/S-1-im　derived　from　the　impregnation　route,　and　0.27Pd/ZSM-5-H　prepared　after　reduction　at　500　degrees　C　in　10　vol%　H-2　).　Furthermore,　the　0.28Pd/S-1-H　sample　possessed　good　thermal　stability　and　its　partial　deactivation　due　to　CO2　or　H2O　introduction　was　reversible,　but　SO2　addition　resulted　in　an　irreversible　deactivation.　The　possible　pathways　of　toluene　oxidation　over　0.28Pd/S1-H　was　toluene　-＞　p-methylbenzoquinone　-＞　maleic　anhydride,　benzoic　acid,　benzaldehyde　-＞　carbon　dioxide　and　water.　We　conclude　that　the　good　dispersion　of　Pd　NPs,　high　adsorption　oxygen　species　concentration,　large　toluene　adsorption　capacity,　strong　acidity,　and　more　Pd0　species　were　responsible　for　the　good　catalytic　performance　of　0.28Pd/S-1-H.　(C)　2022　The　Research　Center　for　Eco-Environmental　Sciences,　Chinese　Academy　of　Sciences.　Published　by　Elsevier　B.V.