Bifunctional metal/base catalysts (Pt/X) for the direct synthesis of MIBK from acetone

The synthesis of MIBK was studied over Pt supported on NaX and CsX zeolites. The activity increased as both the temperature and the H-2/Ac ratio were increased. Temperature had also a beneficial effect on the selectivity to MIBK but the H2/Ac ratio had an opposite effect. Activities and selectivities were always higher for Pt/NaX than for Pt/CsX. For Pt/NaX, increasing the reduction temperature increased the activity but decreased the selectivity to MIBK. Both catalysts were quite stable and selectivities to MIBK of 70% were obtained over PtNaX at 613 K and H-2/Ac = 0.5. The absence of both strong acidic and strong basic sites and a proper balance between metallic and basic sites are responsible for the behavior observed. (C) 2002 Elsevier Science (USA).