空气氧化处理活性炭载体对铜基CO-SCR催化剂性能的影响

Effect of active carbon support treated by air oxidation on the performance of Cu-based catalysts in CO-SCR reaction

采用空气氧化法对活性炭(AC)在不同温度条件下进行了处理,对处理前后活性炭试样进行了低温N2吸脱附、程序升温、Boehm滴定和X射线衍射表征。以处理前后的活性炭作为铜基催化剂载体制备得到Cu/AC、Cu/AC-300、Cu/AC-400和Cu/AC-500催化剂,并对4种催化剂进行了COSCR反应性能测试。试验结果表明:随着空气氧化处理温度的升高,AC的比表面积逐渐增大,表面酸性位数量逐渐增多,Cu/AC催化剂上Cu的分散度逐渐提高。结合载体和催化剂的表征可知,Cu/AC催化剂的表面酸性位数量越多,低温CO-SCR活性越好;在保证表面酸性位数量的条件下,CuO的分散度越高,催化剂的活性温度越低。

Activated carbon(AC)is treated by air oxidation at different temperatures.The AC samples before and after treatment are characterized by low-temperature N2 adsorption desorption,temperature programmed,Boehm titration and X-ray diffraction.Cu/AC,Cu/AC-300,Cu/AC-400 and Cu/AC-500 catalysts are prepared by using the activated carbon before and after treatment as the support.The CO-SCR reaction performance of the four catalysts is tested.The results show that with the increase of air oxidation temperature,the specific surface area of AC increases,the number of surface acid sites increases,and the dispersion of Cu increases.According to the characterization of support and catalysts,the more surface acid sites,the better the low-temperature CO-SCR activity.The higher the dispersion of CuO,the lower the activity temperature of the catalysts under the condition of ensuring the number of surface acid sites.