Hierarchical Pt/NiO hollow microspheres with enhanced catalytic performance

Hierarchical macro-mesoporous Pt/NiO hollow microspheres are synthesized and used for catalytic decomposition of formaldehyde in air at room temperature. The uncalcined Pt-Ni(OH)₂ sample exhibits low catalytic activity. The Pt/NiO sample heated at 300 °C shows significantly enhanced catalytic activity. The Pt/NiO sample at 400 °C exhibits the highest catalytic activity, mainly due to its bimodal macro-mesoporous structure with open and accessible pores, which provides a large specific surface for HCHO adsorption and Pt dispersion, enables the fast diffusion and transport of gas molecules, and ensures the accessibility of active sites on Pt nanoparticles for gas molecules. Moreover, all Pt/NiO hollow spheres have higher catalytic activity than Pt-decorated commercial NiO. The prepared hierarchical macro-mesoporous Pt/NiO nanocomposite hollow microspheres should also find applications in adsorption, photocatalysis, electrocatalysis, separation, and purification processes. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.