The effect of catalyst types on optical emission was studied in N-2 discharge under atmospheric pressure. In silver nanoparticle-loaded MS-13X and HY, purple emissions were observed. On the other hand, green emission was observed in silver nanoparticle-loaded HY. This spectrum had a broadband around 540 +/- 60 nm. It may be flrescence from excited silver on catalyst surface. When toluene adsorbed onto Ag/HY, emission color changed from green to purple in adsorption area only. After catalyst regeneration by O-2 plasma treatment, the emission color returned to green. There, interesting phenomena were important to figure out the mechanism of plasma-catalyst hybrid technology.