정상 및 비정상 온도변화에 따른 린번 천연가스 자동차용 촉매의 정화성능

초록

In this study, we evaluated the CH4 and CO conversion efficiencies over the oxidation catalysts for natural gas vehicle with lean-burn system. On the fresh catalyst, the conversion efficiency was increased when the loading of precious metal was increased. On the aged catalyst, the conversion efficiency was decreased as increasing the excess air ratio. We could confirm the measuring conversion efficiency of the unsteady state with the FTIR and that of steady state with the GC. The temperature increasing ratio of unsteady state is acceptable from 3℃/min. to 15℃/min. for the evaluation of catalyst conversion performance , which has within the 4% of the difference of conversion efficiency. We observed a physical behavior of the thermal aged catalyst´s surface using TEM and BET device. It was found that the precious metal was grown to the micro-scopic size by thermal aging process.

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