TiO2 광촉매 상에서 에틸렌의 완전 산화반응에 대한 연구 :

산소와 수분 및 백금의 첨가 영향

박달령, 안범종*, 박형상**, 히로미 야마시타***, 마사카주 안포***

한국가스공사 연구개발원 가스이용기기연구센타, 한국산업기술대학교 화학공학과, 서강대학교 화학공학과, 일본 오사카 부립대학교 응용화학과

Photocatalytic Oxidation of Ethylene to CO2 and H2O on Ultrafine Powdered TiO2 Photocatalysts: Effect of the  Presence of O2 and H2O and the Addition of Pt

Dal-Ryung Park, Bum-Jong Ahn*, Hyung-Sang Park**,

Hiromi Yamashita*** and Masakazu Anpo***

Center for Gas Utilization Technology(CGUT), R&D Division, Korea Gas Corporation, Korea Polytechnic University, Dept. of Chemical Eng.

Department of Chemical Engineering, Sogang University Seoul, Korea**

Department of Applied Chemistry, College of Engineering, Osaka Prefecture Univ.

Photocatalysis of titanium oxide semiconductors has recently received considerable attention in relation to a variety of applications for environmental issues such as the purification of polluted air and water. As one of the most popular photoactive catalysts, TiO2 photocatalysts have long been investigated in their different forms as bulk materials, colloidal suspension, and dispersed into SiO2 matrices and on porous supports such as zeolites and porous vycor glass. Although the utilization of extremely small powdered TiO2 particles has attracted a great deal of attention as photocatalysts due to their high photocatalytic reactivities, the actual factors controlling the photocatalytic activity of TiO2 particles are still unknown, except for a few important factors such as the magnitude of the band gap, surface area, and crystallinity. Such difficulties mainly arise because the photocatalytic effectiveness of the fine particles varies greatly with their chemical and physical properties as well as their chemical and physical molecular environments.

The complete photocatalytic oxidation of C2H4 with O2 into CO2 and H2O has been achieved on ultrafine powdered TiO2 photocatalysts and the addition of H2O was found to enhance the reaction. The details of the photocatalytic reaction has been studied by IR, ESR, and analysis of the reaction products. UV irradiation of the photocatalysts at 275K led to the photocatalytic oxidation of C2H4 with O2 into CO2, CO, and H2O. The large surface area of the photocatalyst is one of the most important factors in achieving a high efficiency in the photocatalytic oxidation of C2H4. The photo-formed OH species as well as O-2 and O-3 anion radicals play a significant role as a key active species in the complete photocatalytic oxidation of C2H4 with O2 into CO2 and H2O. Interestingly, small amount of Pt addition to the TiO2 photocatalyst increased the amount of selectively formation of CO2 which was the oxidation product of C2H4 and O2.