Isobutane Dehydrogenation over Supported Platinum Acid–Base AlGaPON Catalysts

Isobutane dehydrogenation was studied on platinum impregnated galloaluminophosphate AlGaPO and nitrided galloaluminophosphates AlGaPON, in a conventional continuous flow microreactor system at 500°C. By comparison with AlPO(N), it is shown that gallium plays an important role in the catalytic process by increasing the selectivity of the transformation for isobutene. An isobutene yield of 62% was obtained for a platinum impregnated AlGaPON sample containing 11.8 wt%N, whereas the platinum impregnated precursor AlGaPO only converts isobutane to isobutene with a yield of 49% under similar reaction conditions. This indicates the participation of the basic sites, created by nitridation, to the catalytic conversion of isobutane on Pt/AlGaPON. Both catalysts deactivate with time on stream, due to the deposition of carbonaceous species on the surface, but the activity decay is delayed on the less acid nitrided samples.