Effect of grinding on the physico-chemical properties of Mg-Al hydrotalcite and its performance as a catalyst for Baeyer-Villiger oxidation of cyclohexanone

•First report on HT grinding as means of boosting catalytic performance.•First evidence of grinding-induced segregation of Al to the HT surface.•Short grinding causes surface hydrophilization, prolonged hydrophobization.•Catalytic activity depends on tuning ground HT crystallinity and hydrophilicity.•Optimum grinding time improves ε-caprolactone yield by 50%.