Hierarchical Co3O4-NiO hollow dodecahedron-supported Pt for room-temperature catalytic formaldehyde decomposition

Abstract

Room-temperature catalytic decomposition is considered a predominant approach for the continuous and efficient elimination of indoor formaldehyde (HCHO). Herein, Co3O4-NiO hollow dodecahedra were prepared by using ZIF-67 as a precursor and decorated with 0.3 wt% platinum nanoparticles (Pt NPs). The hierarchical porous Pt/Co3O4-NiO catalyst exhibited an excellent room-temperature HCHO decomposition performance, and 93% conversion was achieved within 60 min. Numerous active oxygens at the interface between Co3O4 and NiO and the oxygen vacancies generated during Pt deposition were favorable for the adsorption and conversion of HCHO to dioxymethylene (DOM). Moreover, the electron transfer from NiO to Pt rendered Pt NPs more effective in adsorbing and activating O2 molecules, thereby promoting the further oxidation of DOM to formate and CO2. Importantly, the hierarchical structure of the Co3O4-NiO support with a large surface area participated in the uniform distribution and easy accessibility of Pt active sites. In addition, the hollow and porous structure enabled Pt/Co3O4-NiO catalyst to possess ultra-low gas resistance, which is important for gas–solid HCHO oxidation. This work may provide clues for the fabrication of MOF-derived catalysts for HCHO decomposition with high efficiency.