0D/2D CeO2 quantum dot/NiO nanoplate supported an ultralow-content Pt catalyst for the efficient oxidation of formaldehyde at room temperature

Abstract

The development of cost-effective and high-powered catalysts to completely decompose formaldehyde (HCHO) into CO₂ and water at room temperature is an important challenge. In this study, we employed a hydrothermal method, followed by an impregnation-chemical reduction, to successfully obtain the hybrid architecture of a 0D/2D CeO₂ quantum dot (QD)/porous NiO hexagonal nanoplate supported ultralow-content (0.08 wt%) Pt. 0D/2D CeO₂/NiO composite supported Pt (Pt/NiCe4) with Ce/Ni molar ratio of 1 : 6 showed an HCHO removal efficiency of 87% in an hour, which was significantly higher than that of Pt/CeO₂ (56%) and Pt/NiO (54%). The improved catalytic activity of Pt/NiCe4 is due to the unique morphology of CeO₂ QDs deposited over the NiO nanoplates, leading to more exposed active sites and close contact of the components on a large scale, and a large amount of the active surface oxygen species stemmed from the insertion of Ni into the CeO₂ lattice and the crucial role of Pt in the activation of O₂ from air. Moreover, the possible reaction mechanism for HCHO oxidation over Pt/NiCe4 was proposed based on the results of the in situ diffused reflectance infrared Fourier transform spectroscopic studies and the performance test. This study may provide a new enlightenment for constructing versatile catalysts for application in indoor air purification.