Novel functional TiPO/SiO2 catalyst enriched surface hydroxyl groups for highly selective catalytic oxidation of cyclohexylamine to cyclohexanone oxime

•The novel TiPO/SiO2 catalyst exhibits excellent catalytic activity and stability.•Rich surface titanium hydroxyls act as the main catalytic active sites.•The catalytic reaction pathway for cyclohexylamine oxidation was revealed.•The energy barrier for NH cleavage is lower than those of α-CH bond cleavage.•This work affords the new insight into the selective oxidation of cyclohexylamine.