Hydrolytic cleavage of lignin derived C-O bonds by acid/base catalysis in water

Hydrolytic cleavage of C–O bond was systematically studied in acidic/alkaline aqueous solution. For phenethoxybenzene (PEB) hydrolysis, 2-phenylethanol and phenol were formed as main products in AlCl 3 solutions, whereas styrene was preferred with Na 2 CO 3 . After a quantitative evaluation of the kinetics of elementary steps, it was concluded that both AlCl 3 and Na 2 CO 3 promoted protons assisted C–O bond scission in H 2 O, whereas alkaline enhanced the dehydration of produced 2-phenylethanol. Kinetic and isotope labeling experiments demonstrated that the hydrolytic rates of PEB were first order with respect to substrate concentrations, hydrolytic cleavage of C–O bond was rate-determining step. The study shed light on the promotional effects and hydrolytic mechanism over acid/base-catalyzed lignin depolymerization in water. Graphic abstract