In this study, a catalyst mixture of activated Mg/Al hydrotalcite as solid base and Pd on carbon nanofibers was investigated for the single-stage liquid-phase synthesis of methyl isobutyl ketone (MIBK) from acetone and H-2 at 313 K and H-2 pressures of 1-20 bar. With this catalyst system acetone and H-2 are selectively converted into MIBK in a single reactor, even at 1.2 bar H-2. Although the hydrogenation of one of the intermediates, mesityl oxide (MO), at 1.2 bar suffers from severe mass transfer limitations in 112, the catalytic activity in the single-stage synthesis is stable over several hours if the steady-state concentration of MO is kept low. Under the presented conditions the dehydration reaction of diacetone alcohol to MO is rate limiting in the production of MIBK. (C) 2004 Elsevier B.V. All rights reserved.