The invention belongs to the technical field of gas purification treatment, relating to a catalyst for removing low-concentration
formaldehyde in gases and the application thereof. The catalyst is characterized by using at least two of Ag, Co, Fe and Cu as main
active components which are loaded on an HZSM-5 type
molecular sieve carrier and are 1-20 percent by weight of the catalyst. The catalyst is filled in a reactor and applied to two alternately operating stages, i.e. a storage stage and a regeneration stage, wherein the reactor can be inflated with
ozone, can be used for heating at a controlled temperature and can carry out DBD (
Dielectric Barrier Discharges). At the storage stage, low-concentration
formaldehyde in the gases is firstly stored on the catalyst; and at the regeneration stage,
ozone or
oxygen-contained gas is introduced for heating or carrying out the DBD so that the
formaldehyde stored on the catalyst is fully oxidized into
carbon dioxide and water, wherein the
oxygen content in the introduced
oxygen-contained gas at the regeneration stage is 20-100 percent, and air can be directly used as the oxygen-contained gas at the regeneration stage. In the invention, the provided catalyst with the function of selective storing and
catalytic oxidation on the formaldehyde has the advantages of low
energy consumption and no secondary
pollution, is extremely suitable for removing low-concentration formaldehyde in gases and is particularly suitable for removing formaldehyde pollutants in
indoor air.