Cu2O@TiO2 core-shell microspheres for naphthalene oxidation

New Cu2O@TiO2 core-shell microspheres were successfully prepared for the first time in this paper. The XRD, N-2 adsorption-desorption, SEM, TEM, EDX and XPS characterizations were utilized to investigate the physical and chemical properties. The liquid phase oxidation of naphthalene was also carried out to test their catalytic performance. The characterization results indicating that the Cu2O microspheres were firstly formed by hydrothermal treatment and the rutile TiO2 coating on the surface would be formed by the hydrolysis of tetrabutyl titanate. The Cu2O@TiO2-5.0 catalyst with the molar ratio of copper to titanium species as high as 5.0 has the largest surface area and maximum pore volume resulting from the integrated microspheres with rougher surface thickness of about 6.3 nm, and it showed higher catalytic performance in the liquid phase oxidation of naphthalene. Naphthalene conversion of 43.2%, 1, 4-naphthoquinone selectivity of 26.7% and phthalic anhydride selectivity of 53.4% can be obtained, and it only slightly decreased even after repeated use for 5 times. The method would provide a valuable theoretic reference for the hindrance of Cu2O rapid deactivation and the industrial application of the naphthalene oxidation to produce high valuable chemicals.