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

ABSTRACT

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 H₂ production rate than that of the Cu loaded on TiO₂NT catalyst throughout the entire reaction temperature range. At the reaction temperature of 250°C and 300°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.

KEYWORDS:

• Confinement effect
• TiO₂ nanotubes
• Cu
• oxygen vacancies
• water-gas shift

Acknowledgments

The authors thank for the support from the Analytical & Testing Center, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, China. The authors declare that there is no conflict.

Additional information

Funding

This study is funded by [Natural Science Foundation of Guangdong Province] under Grant [number 2018A0303130212] and [Science and Technology Program of Guangzhou, China] under Grant [number 201803030019].