Au–Pt bimetallic nanoparticles supported on nest-like MnO₂: synthesis and application in HCHO decomposition

Facile synthesis of Au–Pt bimetallic nanoparticles (Au_1−x Pt _x NPs) and mixtures of Au NPs and Pt NPs ((100 % − y)Au/yPt NPs) and their subsequent deposition on nest-like MnO₂ nanostructures were presented. The as-prepared products were characterized by means of UV–visible spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, and energy dispersive spectroscopy. TEM analyses showed that noble metal NPs were evenly dispersed on the surface of nest-like MnO₂ nanostructures and no agglomeration was observed. The as-prepared metal NPs supported catalysts showed higher catalytic activities than MnO₂ nanostructures for oxidative decomposition of formaldehyde (HCHO). The forms of noble metal NPs and Au/Pt molar ratio have significant effects on the catalytic performance, and Au_0.5Pt_0.5/MnO₂ has the highest catalytic activity among all the as-prepared metal NPs supported MnO₂ catalysts, and the temperature for complete decomposition of HCHO reached as low as 313 K. The high catalytic activities of Au_1−x Pt _x /MnO₂ catalysts resulted from the synergistic effect between Au_1−x Pt _x NPs and MnO₂ nanostructure, as well as the synergistic effect between Au and Pt. The current Au_1−x Pt _x /MnO₂ catalysts are among the first trials to apply bimetallic NP-supported catalysts to the decomposition of HCHO, and proved that the Au_1−x Pt _x /MnO₂ catalysts are promising for indoor decomposition of formaldehyde due to their easy synthesis, low cost, and excellent catalytic performance.