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 degreesC. By comparison with AIPO(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. (C) 2001 Academic Press.