Excellent low-temperature activity for oxidation of benzene serials VOCs over hollow Pt/CoMn2O4 sub-nanosphere: Synergistic effect between Pt and CoMn2O4 on improving oxygen activation

•Synthesis of hollow CoMn2O4 spinel sub-nanosphere by carbon sphere template method.•Loading ultra-low Pt on CoMn2O4 for low-temperature benzene series VOCs oxidation.•Excellent catalytic oxidation activity over Pt/CoMn2O4 even in presence of H2O.•Enhancing O2 activation on the interface of Pt and CoMn2O4 as the active sites.•Improve supplement of active oxygen species by synergistic effect of Pt and CoMn2O4.