Volatile organic pollutants such as benzene and formaldehyde are commonly detected in the ambient air of paper mills. To remove these pollutants from the air, a photo-catalytic reactor was developed in this study. The reactor had a series of honeycomb aluminum meshes coated with nanosized titanium dioxide as the catalyst for the degradation reactions of gaseous pollutants. Both formaldehyde and benzene could be completely degraded in the reactor. However, the degrading time for benzene was much longer than that for formaldehyde, and the degradation rate of benzene decreased with increasing initial benzene concentration. It was found that the reaction pathway for formaldehyde in the mixture was different from that in its single component form, and it took about two times longer time to be degraded than that for its single component form. The reaction pathway of benzene was similar in either case although the degradation time for benzene was about 50% shorter in the mixture form.