Noble-Metal-Free NOx Storage over Ba-Modified TiO2 Photocatalysts under UV-Light Irradiation at Low Temperatures

摘要

Photoassisted nitrogen oxide (NOx) storage was investigated over the barium-modified titanium dioxide (Ba/TiO2) photocatalysts under UV-light irradiation at a high concentration of nitrogen monoxide (NO) of 200 ppm and a high gas hourly space velocity (GHSV) of 50 000 h(-1). The NO removal efficiency was kept >99% during the 1020 s interval from the start of the reaction over the Ba/TiO2 photocatalyst. The temperature-programed desorption (TPD) measurement and X-ray diffraction (XRD) technique revealed that barium oxide (BaO) species functioned as a NOx storage material even at low temperatures, which result in improvement of the performance of the photoassisted NOx storage.