Synergetic modulation of molecular oxygen activation and surface acidity/basicity on defective M/UiO-66m (M = Pt, Pd) for advanced oxidation of gaseous formaldehyde at room temperature

Molecular oxygen (O2) dominated room temperature catalytic oxidation (RTCO) technique is essential for removing indoor formaldehyde (HCHO) and guaranteeing indoor air safety. However, RTCO is challenged by low O2 activation efficiency and uncontrollable O2 activation pathway. In this study, defective UiO-66 (UiO-66m) with abundant coordinatively unsaturated Zr-sites (Zr-CUSs) is exploited for anchoring well-dispersed noble metals (M = Pt, Pd) and tuning surface acidity/basicity. The strong interfacial electronic metal support interactions at Zr-CUSs–M active centers trigger O2 activation into mobile ROS (superoxide radicals (•O2−), singlet oxygen (1O2)) at room temperature. Consequently, adsorbed HCHO can be efficiently oxidized into CO2 with exceptional mineralization efficiency (over 90%) and considerable recyclability (6 runs, 6 h). A novel ROS-initiated advanced oxidation pathway, together with the synergetic acid/base catalytic effects, is proposed based on in situ spectroscopic studies. This study will provide new insights into the O2 activation pathway and designing advanced RTCO catalysts.