A theoretical study on the decomposition mechanisms of deprotonated glycolic acid

► The pathways for the decomposition of glycolate were identified. ► Two new pathways were found for the H2 elimination from glycolate. ► The previously proposed α-lactone intermediate proved to be not involved in the H2 elimination pathways. ► The previously proposed pathways for CO and CH2O elimination from glycolate were confirmed. ► The mechanisms and energy barriers obtained in this work well rationalize the previous experimental observations.