Enhancing catalytic activity for toluene and acetone oxidation over ZraCo1-aOx catalysts by doping Zr to improve the oxygen activation capacity due to formation of Zr-O-Co bonds

Transition metal oxides are considered as effective catalysts for eliminating volatile organic compounds (VOCs) due to their superior characteristics of abundant reserves and low price. A series of ZraCo1-aOx composite oxides was synthesized through a facile hydrothermal method and applied for catalytic oxidation of toluene and acetone. The catalytic activity of ZraCo1-aOx is improved by adjusting the elemental content composition, especially the Zr0.4Co0.6Ox sample exhibits the superior catalytic ability for both toluene (T90 = 231 °C) and acetone (T90 = 208 °C) oxidation under WHSV of 40,000 mL·g−1·h−1. The doping of Zr in ZraCo1-aOx induces to form Zr-O-Co bonds and enlarges the specific surface area compare with pure Co3O4, which improves the redox capacity and increase active oxygen content. In situ DRIFTS tests were used to detect reaction intermediates in the toluene and acetone oxidation process on the catalyst surface, and the advantageous function of Zr doping on promoting activation of oxygen was further determined. Furthermore, the outstanding activity stability and water resistance of the Zr0.4Co0.6Ox catalyst facilitate its application in industrial environments. This work provides a theoretical basis for preparing the catalyst to eliminate VOCs in industrial applications.