Lattice Compressive Strain of Co 3 O 4 Induced by Synthetic Solvents Promotes Efficient Oxidation of Benzene at Low Temperature.

A series of Co 3 O 4 with different surface defective structures were prepared by the solvothermal method and tested for the activity of benzene oxidation. The characterizations revealed that the synthetic solvent had a dramatic effect on the composition of Co 3 O 4 precursors as well as the physicochemical properties of Co 3 O 4 . Although all Co 3 O 4 exhibited a cubic spinel structure, Co 3 O 4 prepared with triethylene glycol (Co-TEG) had the highest compressive strain due to the nature of high viscosity of triethylene glycol. These in turn affected the surface chemical structure and the low-temperature redox properties. Co-TEG exhibited the best benzene oxidation activity and showed excellent stability and good water resistance. In situ diffuse reflectance infrared Fourier transform spectroscopy was used to study the oxidation process of benzene. It was found that Co-TEG with more defective structures had abundant surface adsorbed oxygen and active lattice oxygen, which promoted the conversion of benzene and the corresponding intermediates at low temperature.