Reduction of NO with CH4 over platinum supported on cobalt phosphate catalyst

Selective reduction of NO with CH4 On platinum supported on cobalt phosphat e was investigated. It was found that Pt/Cos(3)(PO4)(2) exhibits the high a ctivity to NO reduction with CHI. NO conversion increased with increasing a mount of Pt loading and it attained to a maximum activity at 1 wt% Pt. Conv ersion of NO was always higher than that of NO2 on Pt/Co-3(PO4)(2) under th e same condition. This result suggested that the reduction of NO was procee ded not through the formation of NO2 or NO3- as intermediate species but th rough the direct decomposition of NO as a primary reaction. NO conversion i ncreased with decreasing oxygen partial pressure and the high conversion of NO into N-2 was exhibited when no oxygen was coexisted. Temperature progra mmed desorption (TPD) measurement suggested that loading Pt accelerates the dissociative adsorption of NO and weakened the adsorption of O-2. Therefor e, it seems that NO decomposition on Pt/Co-3(PO4)(2) was initiated by the d issociative adsorption of NO. Coexisting CH4 removed the formed oxygen whic h strongly adsorbed on the catalyst and recovered the active site. This stu dy reveals that Pt supporting on CO3(PO4)(2) is highly active for the reduc tion of NO with CH4.