A　series　of　Pd/Al2O3-m　catalysts　with　high　activity　and　good　stability　for　dehydrogenation　of　dodecahydro-N-ethylcarbazole　have　been　developed　by　tuning　the　interaction　between　Pd　and　mesoporous　Al2O3,　which　was　achieved　by　adjusting　the　calcination　temperature　of　the　support　and　the　loading　of　Pd.　The　results　showed　that　the　calcination　temperature　of　the　support　affected　the　particle　size　and　chemical　state　of　Pd　species　by　influencing　the　content　of　defective　Al　species　and　acidity　in　the　supports.　The　loading　of　Pd　was　closely　related　to　the　number　of　active　sites　that　can　be　provided　by　the　catalysts,　and　too　low　or　too　high　is　detrimental　to　the　catalytic　dehydrogenation　reaction.　When　the　calcination　temperature　was　600　°C　and　the　Pd　loading　was　2.0　wt%,　Pd2.0/Al2O3-m(600)　catalyst　showed　the　highest　catalytic　activity,　with　a　dodecahydro-N-ethylcarbazole　conversion　of　100%,　H2　release　amount　of　5.72　wt%　and　dehydrogenation　efficiency　of　98.66%.　Meanwhile,　this　catalyst　possessed　a　good　dehydrogenation　stability,　with　a　dehydrogenation　efficiency　of　still　over　80%　after　8　cycles　of　dehydrogenation.　These　improvements　in　catalytic　activity　benefited　from　the　smaller　Pd　NPs　and　a　suitable　Pdδ+/Pd0　ratio.　Besides,　Pd2.0/Al2O3-m(600)　catalyst　also　demonstrated　the　excellent　versatility,　showing　high　dehydrogenation　activity　for　dodecahydro-N-propylcarbazole,　octahydro-2-methylindole　and　octahydro-1,2-dimethylindole,　which　dehydrogenation　efficiency　are　99.67%,　100%,　and　100%,　respectively.　©　2025　Elsevier　Ltd