Copper and lanthanum mixed oxides as catalysts for ethanol Guerbet coupling: The role of La3+ on the production of long‐chain alcohols

Abstract

AbstractMixed oxides derived from the calcination of modified hydrotalcites precursors with copper and lanthanum were synthetized by the co‐precipitation method and characterized and applied as catalysts for ethanol Guerbet coupling reactions. The oxides obtained were used to convert ethanol into 1‐butanol and long‐chain alcohols, mostly 1‐hexanol. The selectivity for 1‐butanol and 1‐hexanol reached 62% and 10% for Cu‐MgAl(O) at 280°C. The addition of 1 mol% of La3+ (CuLa‐MgAl(O)) increased the number of basic sites comparing to Cu‐MgAl(O) changing the selectivity for 1‐butanol and 1‐hexanol reaching 16.70 and 41.7% at 280°C. The addition of lanthanum and consequently the increase on the catalyst basicity was related to the obtainment of long‐chain alcohols due to the enolate formation during the aldol condensation of Guerbet coupling.