Selective reduction of NO with CH4 on platinum supported on cobalt phosphate was investigated. It was found that Pt/Co3(PO4)2 exhibits the high activity to NO reduction with CH4. NO conversion increased with increasing amount of Pt loading and it attained to a maximum activity at 1 wt% Pt. Conversion of NO was always higher than that of NO2 on Pt/Co3(PO4)2 under the same condition. This result suggested that the reduction of NO was proceeded not through the formation of NO2 or NO3- as intermediate species but through the direct decomposition of NO as a primary reaction. NO conversion increased with decreasing oxygen partial pressure and the high conversion of NO into N2 was exhibited when no oxygen was coexisted. Temperature programmed desorption (TPD) measurement suggested that loading Pt accelerates the dissociative adsorption of NO and weakened the adsorption of O2. Therefore, it seems that NO decomposition on Pt/Co3(PO4)2 was initiated by the dissociative adsorption of NO. Coexisting CH4 removed the formed oxygen which strongly adsorbed on the catalyst and recovered the active site. This study reveals that Pt supporting on Co3(PO4)2 is highly active for the reduction of NO with CH4.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)