Pt/C@MnO2 composite hierarchical hollow microspheres for catalytic formaldehyde decomposition at room temperature

Abstract

Hierarchical carbon@manganese oxide (MnO2) core-shell heterostructure was fabricated by a facile hydrothermal method with hollow carbon spheres as a sacrificial template, and then deposited with platinum (Pt) nanoparticles (NPs). The as-prepared Pt/C@MnO2 composite catalyst exhibited superb performance for removing formaldehyde (HCHO) at room temperature compared with the Pt loaded on MnO2 microspheres or commercial MnO2. The MnO2 nanosheet-assembled hierarchical architecture endowed Pt/C@MnO2 with larger specific surface area and open porous structure, which not only promotes the high dispersity of Pt NPs but also facilitates the diffusion and adsorption of HCHO onto the catalyst surface. The abundant surface active oxygen species resulted from the activation and dissociation of O2 adsorbed at oxygen vacancies adjacent to Pt NPs, and were identified as the primary active species for converting HCHO into intermediates such as dioxymethylene, formate and carbon monoxide. This work might provide enlightenment for designing morphology-dependent and highly active catalysts for HCHO elimination at ambient temperature.