LAUSR

As a main pollutant in indoor environments, formaldehyde has high toxicity and a long release period. The use of catalytic-oxidation technique to remove formaldehyde can effectively improve indoor air quality. Spinel Co3O4 is an inexpensive catalyst with good low-temperature catalytic activity for formaldehyde oxidation. This paper systematically reviews the progress of research on Co3O4-based catalysts for formaldehyde oxidation in recent years. First, the limited performance of pristine Co3O4 and influencing factors (e.g., morphology, crystal face exposure, surface oxygen vacancy, surface reactive species, and environmental factors) is described. Subsequently, we introduce current modification methods to improve catalytic activity, including Co3O4/transition metal oxide composites, Co3O4-supported noble metals, and alkali-metal-ion doping. The reaction mechanism of catalytic oxidation for formaldehyde on Co3O4-based catalysts is also discussed. Finally, perspectives on challenges related to Co3O4 catalysts for formaldehyde oxidation are proposed.