Highly efficient synthesis of pseudoionone from citral with acetone on Li-doped La2O3­ZnO catalysts

A highly efficient Li/La ₂ O ₃ -ZnO catalysts was developed for aldol condensation of citral and acetone. Li/La ₂ O ₃ ­ZnO catalysts with different Li ⁺ loading were prepared by coprecipitation method followed by incipient wetness impregnation method, and were characterized by XRD, BET, FT-IR, SEM. The results demonstrated that Li was well dispersed on La ₂ O ₃ ­ZnO composite oxide, may coordinate with chemisorbed O ²⁻ species to form active strong basic site. Therefore, Li introduced promoted the formation of active strong base sites, then significantly improved the catalytic performance. The suitable preparation conditions of catalyst were Li ⁺ loading of 4.0 wt%, calcination temperature of 300°C after Li-doped, and impregnation time of 15 h. The conversion of citral and yield of pseudoionone were 100% and 99.2% respectively under the suitable reaction conditions of catalyst dosage of 0.5 g, reaction temperature and time was 50°C and 3 h, and citral/acetone molar ratio of 1:9. Topical Heading : Reaction Engineering, Kinetics and Catalysis