The synthesis of isobutyl alcohol ((BuOH)-Bu-i) from methanol (MeOH) and n-propanol (PrOH) through the Guerbet condensation has been studied at 200 degreesC and under inert atmosphere (3.0 MPa of N-2) using a two-component heterogeneous catalytic system based on pre-activated copper chromite and Mg-Al mixed oxides deriving from hydrotalcite-type (HT) precursors with different Mg/Al ratios. All the investigated catalysts displayed a significant activity, with an almost complete selectivity to TuOH. Unlike the copper chromite/soluble sodium methoxide system, the catalysts were tolerant of the co-produced water and did not display any appreciable deactivation during the course of the reaction. The catalyst productivity was found to increase by reducing the Mg/Al ratio in the heterogeneous base, according to the increase of the fraction of medium-strong and strong basic sites which favour the aldol condensation between the aldehydes derived from MeOH and PrOH. (C) 2004 Elsevier B.V. All rights reserved.
Guerbet condensation of methanol with n-propanol to isobutyl alcohol over heterogeneous copper chromite/Mg-Al mixed oxide catalysts
CARLINI, CARLO;RASPOLLI GALLETTI, ANNA MARIA;SBRANA, GLAUCO;
2004-01-01
Abstract
The synthesis of isobutyl alcohol ((BuOH)-Bu-i) from methanol (MeOH) and n-propanol (PrOH) through the Guerbet condensation has been studied at 200 degreesC and under inert atmosphere (3.0 MPa of N-2) using a two-component heterogeneous catalytic system based on pre-activated copper chromite and Mg-Al mixed oxides deriving from hydrotalcite-type (HT) precursors with different Mg/Al ratios. All the investigated catalysts displayed a significant activity, with an almost complete selectivity to TuOH. Unlike the copper chromite/soluble sodium methoxide system, the catalysts were tolerant of the co-produced water and did not display any appreciable deactivation during the course of the reaction. The catalyst productivity was found to increase by reducing the Mg/Al ratio in the heterogeneous base, according to the increase of the fraction of medium-strong and strong basic sites which favour the aldol condensation between the aldehydes derived from MeOH and PrOH. (C) 2004 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
