Calcined Mg/Al hydrotalcites (CHT) with various atomic ratios of Mg/Al were prepared and used as support. One-step synthesis of methyl isobutyl ketone (MIBK) from acetone and hydrogen at atmospheric pressure was investigated over Pd/ CHT and Ni/CHT catalysts. These catalysts showed high activities and high selectivities to MIBK, reaching 60-70% selectivity at 35-40% conversion in some experiments. A temperature of ca. 140 degrees C was sufficiently high for the calcined hydrotalcite-supported catalyst to assume basic properties and good activities in MIBK synthesis. The loading of metal (or the density of metal sites) was an important factor for product distribution in MIBK synthesis. A strong metal-support interaction was exhibited in these catalysts. A higher reduction temperature (>500 degrees C) was needed for Ni/CHT catalysts to assume considerable reactivity and selectivities. The reduction temperature played an important role in the behavior of the Ni/CHT catalysts. (C) 1998 Elsevier Science B.V.
