Role of Hydroxyl Groups in Low-Temperature CO Catalytic Oxidation over Zn4Si2O7(OH)2 Nanowire-Supported Gold Nanoparticles

Abstract

Zn4Si2O7(OH)2 nanowires (ZSO) with abundant hydroxyl groups can be easily fabricated by a hydrothermal method. Gold nanoparticles supported on ZSO catalysts were prepared by a deposition–precipitation method and exhibited superior catalytic activity in CO oxidation at low temperatures. X-ray photoelectron spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy suggested that the metal–support interactions and abundant hydroxyl groups existed in the ZSO catalysts were beneficial to CO oxidation. The influence of gold contents and calcination temperature on their catalytic performance was also investigated. Obtained results demonstrated that the 0.8% Au–ZSO catalysts pretreated at 300 °C exhibited excellent CO catalytic activity and long-term stability. On the basis of experiment results, a possible mechanism was illustrated in atomic scale by density functional theory analysis to reveal the role of hydroxyl groups in CO oxidation for the Au–ZSO catalyst.