Highly Dispersed Ni Atoms and O 3 Promote Room-Temperature Catalytic Oxidation.

Transition metal oxides are promising catalysts for catalytic oxidation reactions but are hampered by low room-temperature activities. Such low activities are normally caused by sparse reactive sites and insufficient capacity for molecular oxygen (O 2 ) activation. Here, we present a dual-stimulation strategy to tackle these two issues. Specifically, we import highly dispersed nickel (Ni) atoms onto MnO 2 to enrich its oxygen vacancies (reactive sites). Then, we use molecular ozone (O 3 ) with a lower activation energy as an oxidant instead of molecular O 2 . With such dual stimulations, the constructed O 3 -Ni/MnO 2 catalytic system shows boosted room-temperature activity for toluene oxidation with a toluene conversion of up to 98%, compared with the O 3 -MnO 2 (Ni-free) system with only 50% conversion and the inactive O 2 -Ni/MnO 2 (O 3 -free) system. This leap realizes efficient room-temperature catalytic oxidation of transition metal oxides, which is constantly pursued but has always been difficult to truly achieve.