Efficient and economical technologies are essential to the control of mercury, the emission of which imposes serious health concerns and environmental risks. Photocatalysis is an attractive method for reducing mercury emissions. Considering that titania is widely applied in the photodegradation of toxic contaminants, this study investigated the removal of mercury over cerium based titania nanofibers (CBTs) at low temperature. According to the results, in the atmosphere containing SO2, both catalyst and UV proposed adverse effect on Hg-0 oxidation. The competition between SO2 and Hg-0 for active sites and the formation of cerium sulfate are responsible for the deactivation of Hg-0 removal capacity. More interestingly, without OD NO and HCl still exerted a superior promoting effect on mercury removal. Entirely different from the properties under SO2, UV and catalyst both facilitated Hg-0 oxidation with the existence of HCl. Meanwhile, effects of the copresence of NO and SO, on Hg-0 removal were further investigated. NO was the most dominant gas component enhancing the removal capacity. Considerable high removal efficiency (>80%) was observed in the presence of 300 ppm of NO and 400 ppm of SO2. These indicate that combining photocatalysis technology with CBTs is a promising strategy to oxidize mercury under low-rank coal combustion flue gas in which the concentration of HCl is relatively low.