Earticle

본 연구에서는 대기오염물질인 유해 황산화물 가스를 이산화티탄 촉매 반응기와 연면 방전 반응기를 조합한 반응기에서 플라즈마 방전반응에 의하여 주파수 변화, 체류시간, 전극의 굵기, 첨가 모의가스 등의 공정 변수를 변화 시켜 분해제거 실험을 하였다. 실험 결과 황산화물의 분해제거 실험에서 주파수 10kHz에서 소비전력 19W에서 분해제거율은 99%이었으며 이산화티탄 촉매반응기를 부착한 경우가 없는 경우보다 5%이상 증가효과가 이었다. 첨가가스로 메탄을 첨가한 경우 분해제거율이 증가하였고, 산소농도가 높아질수록 증가하였다 또한 이산화 탄소를 첨가한 경우 분해율은 감소하였다.

WO3-TiO2 catalysts were prepared by an incipient wet-impregnation method for high-temperature selective catalytic reduction (SCR) of NOx. Structure, surface acidity, and catalytic performance of SCR catalyst according to WO3 content (4, 6, 8, and 10 wt.%) were characterized by morphological and spectroscopy analyses. The 10 wt.% WO3-TiO2 catalyst had high conversion efficiency due to the improvement of specific surface area, catalytic acidity, and monolayer capacity of TiO2 support. It was found that tungsten oxide species are dispersed in the interlayer between the grain and the grain boundary of TiO2 support in transmission electron microscopy. The WO3 affected the suppressed grain growth and the improved Brønsted acid sites that could provide much surface acidity by the grain boundary reinforcement. The structural interaction between the proper WO3 content and TiO2 support led to the existence of octahedrally and tetrahedrally coordinated WO3 structures on the surface in the Raman spectra. The enhanced catalytic activity of 10 wt.% WO3-TiO2 is attributed to the increase of the surface acidity (Brønsted acid sites) by the shell formation of WO3 species.