The direct decomposition of NO over the La 2CuO 4 nanofiber catalyst

Abstract

The NO catalytic direct decomposition was studied over La 2CuO 4 nanofibers, which were synthesized by using single walled carbon nanotubes (CNTs) as templates under hydrothermal condition. The composition and BET specific surface area of the La 2CuO 4 nanofiber were La 2Cu 0.88 2+Cu 0.12 +O 3.94 and 105.0 m 2/g, respectively. 100% NO conversion (turnover frequency-(TOF): 0.17 g NO/ g catalyst s) was obtained over such nanofiber catalyst at temperatures above 300 °C with the products being only N 2 and O 2. In 60 h on stream testing, either at 300 °C or at 800 °C, the nanofiber catalyst still showed high NO conversion efficiency (at 300 °C, 98%, TOF: 0.17 g NO/ g catalyst s; at 800 °C, 96%, TOF: 0.16 g NO/ g catalyst s). The O 2 and NO temperature programmed desorption (TPD) results indicated that the desorption of oxygen over the nanofibers occurred at 80–190 and 720–900 °C; while NO desorption happened at temperatures of 210–330 °C. NO and O 2 did not competitively adsorb on the nanofiber catalyst. For outstanding the advantage of the nanostate catalyst, the usual La 2CuO 4 bulk powder was also prepared and studied for comparison.