acid was formed using 1 mol/L sodium hydroxide (pH 14) as the
catalyst which were comparable with the literature reported data [26]. Interestingly, ZrO2 gave the higher yield
of lactic acid than MgO in neutral or weakly acidic/basic aqueous
solutions. An average lactic acid yield of 35.2 ± 2.5% was obtained with the ZrO2 catalyst in the neutral aqueous solution In contrast, lactic acid with a lower yield, ∼22.9%, was
produced over MgO