Abstract
Gaseous NO was photocatalytically reduced at room temperature by photo-assisted selective catalytic reduction (photo-SCR) with ammonia over TiO2 in this study. NO reduction efficiency and N2 selectivity were determined from gases composition at the outlet stream of photoreactor. Effect of operating conditions, e.g. light intensity and inlet concentrations of ammonia and oxygen, on the NO reduction efficiency and N2 selectivity were discussed to determine the feasible operating condition for photocatalytic reduction of NO. Experimental results showed that selective catalytic reduction of NO with ammonia over TiO2 in the presence of oxygen was a spontaneous reaction in dark. The photoirradiation on the TiO2 surface caused remarkable photocatalytic reduction of NO to form N2, NO2, and N2O under 254 nm UV illuminations, while almost 90% of N2 selectivity was achieved in this study. The ammonia and oxygen molecules played the roles of reductant and oxidant for NO reduction and active sites regeneration, respectively. The reduction of NO was found to be increased with the increase of inlet ammonia and oxygen concentrations until specific concentrations because of the limited active sites on the surface of TiO2. The kinetic model proposed in this study can be used to reasonably describe the reaction mechanism of photo-SCR.
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Pârvulescu V, Grange P, Delmon B. Catalytic removal of NO. Catalysis Today, 1998, 46(4): 233–316
Bosch H, Janssen F. Formation and control of nitrogen oxides. Catalysis Today, 1988, 2(4): 369–379
Cho S M. Properly apply selective catalytic reduction for NOx removal. Chemical Engineering Progress, 1994, 90: 39–45
He W, Zhu T, Li J. NO conversion by positive streamer discharge-Effects of gas compositions and reaction conditions. Frontiers of Environmental Science & Engineering in China, 2009, 3(2): 186–193
Huang B, Huang R, Jin D, Ye D. Low temperature SCR of NO with NH3 over carbon nanotubes supported vanadium oxides. Catalysis Today, 2007, 126(3–4): 279–283
Tanaka T, Teramura K, Funabiki T. Photoassisted selective catalytic reduction of NO with ammonia in the presence of oxygen at low temperature. Physical Chemistry Chemical Physics, 2000, 2(12): 2681–2682
Tanaka T, Teramura K, Arakaki K, Funabiki T. Photoassisted NO reduction with NH3 over TiO2 photocatalyst. Chemical Communications, 2002, (22): 2742–2743
Chou Y C, Ku Y. NO reduction and N2 selectivity by photo-SCR under various operating conditions. Chemical Engineering Journal, 2010, 162(2): 696–701
Teramura K, Tanaka T, Funabiki T. Photoassisted selective catalytic reduction of NO with ammonia in the presence of Oxygen over TiO2. Langmuir, 2003, 19(4): 1209–1214
Teramura K, Tanaka T, Yamazoe S, Arakaki K, Funabiki T. Kinetic study of photo-SCR with NH3 over TiO2. Applied Catalysis B: Environmental, 2004, 53(1): 29–36
Yamazoe S, Okumura T, Teramura K, Tanaka T. Development of the efficient TiO2 photocatalyst in photoassisted selective catalytic reduction of NO with NH3. Catalysis Today, 2006, 111(3–4): 266–270
Ku Y, Ma C M, Shen Y S. Decomposition of gaseous trichloroethylene in a photoreactor with TiO2-coated nonwoven fiber textile. Applied Catalysis B: Environmental, 2001, 34(3): 181–190
Ma C M, Ku Y, Chou Y C, Jeng F T. Performance of tubular-type optical fiber reactor for decomposition of VOCs in gaseous phase. Journal of Environmental Economics and Management, 2008, 18: 363–369
Mohseni M, David A. Gas phase vinyl chloride (VC) oxidation using TiO2-based photocatalysis. Applied Catalysis B: Environmental, 2003, 46(2): 219–228
Ma C M, Ku Y, Kuo Y L, Chou Y C, Jeng F T. Effects of silver on the photocatalytic degradation of gaseous isopropanol. Water, Air, and Soil Pollution, 2009, 197(1–4): 313–321
Kim S B, Hong S C. Kinetic study for photocatalytic degradation of volatile organic compounds in air using thin film TiO2 photocatalyst. Applied Catalysis B: Environmental, 2002, 35(4): 305–315
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Chou, Y., Ku, Y. Selective reduction of NO by photo-SCR with ammonia in an annular fixed-film photoreactor. Front. Environ. Sci. Eng. 6, 149–155 (2012). https://doi.org/10.1007/s11783-010-0296-9
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DOI: https://doi.org/10.1007/s11783-010-0296-9