Fe doping modulates defect structures in δ-MnO2 for catalytic oxidation of formaldehyde at room temperature

Formaldehyde (HCHO), a ubiquitous indoor organic pollutant, severely threatens human health. Developing efficient and low-energy catalytic materials for room-temperature HCHO purification remains an urgent priority. In this work, Fe y MnO x catalysts were synthesized via a facile coprecipitation method. The Fe doping effectively modulated the morphology and crystallinity of δ-MnO 2 while inducing the formation of surface oxygen vacancies, thereby enhancing the capability to generate surface reactive oxygen species. Under a gas hourly space velocity (GHSV) of 150 L·g cat –1 ·h –1 , the catalyst achieved > 99 % removal efficiency for 100 ppm HCHO, along with exceptional stability. In situ DRIFTS reveals the influence of Fe doping on the catalytic reaction pathway for HCHO. This work demonstrates that the Fe doping strategy successfully optimizes the microstructure and surface chemical properties of δ-MnO 2 , resulting in outstanding room-temperature HCHO removal performance, providing valuable insights into defect engineering for optimizing transition metal oxide catalysts.