High catalytic activity of pitch based activated carbon fibres of moderate surface area for oxidation of NO to NO2 at room temperature

Catalytic oxidation of NO (380 ppmv) to NO2 over activated carbon fibres of moderate surface area (similar to 800 m(2) g(-1)) at room temperature was carried out, to develop oxidative removal of NO from flue gas. The heat treatment of pitch-based activated carbon fibres of moderate surface area markedly increased the conversion of NO to 87% in dry air, 62% in air of 80% relative humidity and 24% in wet air (100% r.h.) at 25 degrees C and a ratio of fibre mass to gas flow rate of 1.0 x 10(-2) g min mL(-1). The strong inhibiting effect of humidity on the activity of the as-received fibres was moderated by heat treatment of the fibres at 850 degrees C. A lower concentration of 10 ppmv NO markedly reduced the oxidation, the conversions being 24 and 5% in dry and wet (100% r.h.) air respectively. The catalytic activities of other pitch-based fibres of different surface area were also much inferior in moist air above 60% r.h. (C) 1997 Elsevier Science Ltd.