Esterification of lactic acid over TiO2–ZrO2 catalysts

Abstract N-butyl lactate was synthesized with a good yield (the maximum product yield was 95.7% at 140 °C) by the reaction between lactic acid and n-butanol over TiO 2 –Al 2 O 3 catalysts. These catalysts had various Ti/Al atomic ratios (ratio = 1/0, 9/1, 3/1, 1/1, 1/3, 1/9, and 0/1) and were prepared by a co-precipitation method. XRD, n-butylamine adsorption, nitrogen adsorption, and SEM were used to characterize the oxides. The maximum activity was found for the catalyst with Ti/Al atomic ratio = 1 (TA11). The superiority of TA11 was ascribed to its largest surface area and its maximum acidity. Under identical reaction conditions, TA11 catalyst exhibited significantly better activity than the TiO 2 –ZrO 2 catalysts reported earlier, which should be due to the larger surface area of the former.