Catalysts for conversion of ethanol to butanol: Effect of acid-base and redox properties

The effect of acid-base properties of three different supports (hydroxyapatite, ?-Al2O3and MgO) and of the redox properties of dispersed Ru or Ni on the catalytic conversion of ethanol into butanol has been investigated. Catalytic tests have been carried out in the temperature range 200-500 °C by feeding an ethanol/N2mixture to a lab-scale fixed bed reactor of powdered catalyst. Both supports and metal containing materials were deeply characterized by XRD, N2physisorption, CO2and NH3TPD, H2TPR. Highest butanol yields were associated to low ratio between acid and basic centres, typical of MgO, and to the easy reducibility of well dispersed metals as well. Good butanol yields can be also ascribed to the enhancement of both surface area and basicity of MgO provided by metal addition.