Effect of the MgO Activation Conditions on its Basicity and Catalytic Properties”.

V.K. DÍEZ; C.A. FERRETTI; P.A. TORRESI; C.R. APESTEGUÍA; J.I. DI COSIMO

Detroit

Congreso; 22nd. Meeting of the North American Catalysis Society; 2011

North American Catalysis Society

Lately, increasing research efforts have been devoted to the use of solid bases for obtaining fine chemicals, pharmaceuticals and valuable compounds from renewable raw materials.  In particular, pure and promoted MgO has been studied for promoting Cannizzaro and Tischenko reactions, Michael, Wittig and Knoevenagel condensations, olefin isomerizations and the synthesis of organic chemicals by either self- or cross-condensation reactions.  However, the MgO basicity needed for efficiently catalyzing these reactions depend on the rate-limiting step requirements.  For example, MgO is often doped with Li+ cations when stronger basic sites are needed.  In this work, we have investigated the effect of calcination temperature on the MgO basicity, i.e. nature and strength of surface basic sites, and on the catalytic properties.  The activity and selectivity of MgO calcined at increasing temperatures were probed for the cross-aldol condensation of citral with acetone to obtain pseudoionones (PS), the transesterification of methyl oleate (FAME) with glycerol to yield monoglycerides (MG), and the gas-phase hydrogen transfer reaction of mesityl oxide with 2-propanol to form 4-methyl 3-penten 2-ol (UOL).