Effect of metal ion dopants on decomposition formaldehyde room-temperature catalyzed by oxygen-deficient M-MnOx (M=Ce, Co and Cu) materials

Surface vacancy defect engineering is effectively used to enhance catalytic activity in many applications. Herein, the manganese oxide (MnOx) catalysts doped with transition metal (Cerium, Cobalt and Copper) were successfully synthesized and applied for the decomposition of formaldehyde (HCHO) at indoor temperature. In comparison with the MnOx, the doping of cerium and cobalt exposed more defects on the catalysts surface, thereby contributed to more oxygen vacancies. The results show that the M-MnOx (M=Ce, Co) exhibit the enhanced catalysis of HCHO oxidation at ambient temperature through the formation of surface oxygen and the improvement of the redox performance. By contract, the catalytic performance of the Cu-MnOx is slightly restrained compared with that of the pristine MnOx. A mechanism for removing HCHO at indoor temperature was put forward by in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). This study proposes a defect engineering technique to increase surface vacancies though transition metal doping for HCHO decomposition, which is conducive to rational designing the feasible strategy for HCHO decomposition.