Cu nanoparticles confined in TiO2 nanotubes to enhance the water-gas shift reaction activity

It is of great significance to develop water-gas shift (WGS) catalyst with high catalytic activity in low-temperature operational regime. In this paper, we have prepared Cu confined in TiO2 nanotubes (TiO2NT, Cu-in-TiO2NT) catalyst via a vacuum-assisted impregnation method and subsequent calcination. The confined Cu-in-TiO2NT catalyst exhibits the higher CO conversion and H-2 production rate than that of the Cu loaded on TiO2NT catalyst throughout the entire reaction temperature range. At the reaction temperature of 250 degrees C and 300 degrees C, the CO conversion of the confined catalyst is twofold and fourfold, respectively, higher than that of the supported catalyst, demonstrating superior catalytic activity toward WGS reaction. Due to the confinement effect of TiO2NT, the confined Cu-in-TiO2NT catalyst can enhance the concentration of the oxygen vacancies for H2O activation, contributing to the higher WGS activity.