Exceptional formaldehyde oxidation at room temperature on Co single-atom functionalized TiO2 nanowires via highly effective O2 activation

O2 activation is vital for catalyzing the oxidation of formaldehyde (HCHO). Despite the high O2 activation capabilities demonstrated by noble metal catalysts, their practical application is impeded by their exorbitant cost. Herein, Co single atoms were successfully incorporated into titanium dioxide nanowires (TiO2-NWs). Furthermore, the key step in the HCHO catalytic oxidation process was elucidated through in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) and density functional theory (DFT) calculations. Finally, the intricate O2 activation mechanism was explored, revealing the catalyst's exceptional performance in ambient HCHO oxidation. Notably, it outperformed commercial TiO2 (TiO2-P25) by 13.3 times and Co-supported TiO2-P25 by 1.9 times. Co single atoms facilitated the conversion of O2 into superoxide (O2- ), significantly reducing the reaction barrier of dioxymethylene to formate. This superior O2 activation was attributed to the active nature and unsaturated electronic configuration of Co single atoms. This study provides a novel, costeffective strategy for creating HCHO elimination catalysts with accessible nonnoble transition metals.