Using TiO2 photocatalyst with adsorbent to oxidize carbon monoxide in rich hydrogen

Polymer electrolyte fuel cell (PEFC) starts to be used in industries and homes in the world. Hydrogen (H2) is normally used as the fuel to power PEFC. However, the power generation performance of PEFC is harmed by the carbon monoxide (CO) in the H2 that is often produced from methane (CH4). Normally, precious metal catalysts and thermal energy are used to remove CO in rich H2, which are costly. Therefore, an alternative process, i.e. using the TiO2 photocatalyst combined with adsorbent to oxidize the CO is studied in this paper. The purpose of this study is to understand oxidization characteristics and experimental conditions for the alternative process, in order to improve its efficiency. The impacts of initial concentration ratio of O2 to CO, filling volume ratio of the TiO2 particles combined with silica to reactor, and different preparation methods of TiO2 with adsorbent on the CO oxidization performance are investigated. The optimum initial concentration of O2 and best filling volume ratio of the TiO2 particles combined with silica to reactor was found to be 4 vol% and 50 vol%, respectively, under the experimental conditions. By using TiO2 particles combined with mesoporous silica, the concentration of CO in the reactor was reduced from 10 800 ppmV down to 27 ppmV after UV light illumination of 48 h.