Robust oxygen vacancies induced by in situ interfacial engineered NiMn2O4/Mn2O3 heterostructure for durable ozone elimination

Oxygen vacancies (V o ) are the key reactive sites for the decomposition of airborne ozone over Mn-based oxide catalysts, while their stability is still challenging due to the difficulty in desorption of residual oxygen species. Herein, an interfacial engineered NiMn 2 O 4 /Mn 2 O 3 catalyst (NiMnO x ) is in situ constructed from Ni-modified Mn-based metal–organic frameworks, and applied for O 3 decomposition at room temperature. The optimal catalyst exhibits over 96 % of O 3 removal efficiency ([O 3 ] = 40 ppm) after more than 75 h of continuous operation under 50 % relative humidity. Integrated experimental and theoretical findings indicate that the constructed NiMn 2 O 4 /Mn 2 O 3 interface structure induces the charge rearrangement and accelerates charge shuttle across the interface, which reduces the formation energy of V o and promotes the formation of abundant and robust V o , boosting the redox capacity of the catalyst. The unique configuration effectively lowers the adsorption energy barrier of O 3 and inhibits the adsorption of H 2 O, driving the rate-limiting step (decomposition of the second O 3 ) with a negative reaction energy (–0.01 eV), thus significantly enhancing the reaction efficiency under extreme environments. This study presents a novel interfacial engineering strategy for the design of efficient manganese-based catalysts with robust V o , achieving efficient and stable O 3 decomposition.