采用两次沉淀法制备了一系列无载体铜锰复合氧化物催化剂,以NO催化氧化作为目标反应,系统考察了原料液[Cu]/[Mn]比、焙烧温度、焙烧时间等因素对催化剂催化性能的影响。结果表明:在[Cu]/[Mn]=1/6,焙烧温度300℃,焙烧时间8h条件下制备的催化剂具有最优催化氧化NO的活性,在室温下,且不引入任何还原剂的情况下,在6h内将107mg/m3的NO完全消除。此外,原位红外在线检测(FT-IR)结果表明,NO被转化成了亚硝酸盐和硝酸盐,并附着在催化剂表面。
A series of copper manganese oxide catalysts have been prepared using a re-precipitation procedure and evaluated in NO oxidation at room temperature. The effects of varying the Cu/Mn ratio in the reaction mixture,calcination temperature and calcination time on the catalytic activity were investigated in detail. The following optimum preparation conditions were identified with respect to the catalyst activity for the oxidation of NO at room temperature:[Cu]/[Mn]=1/6; a calcination temperature of 300 ℃; a calcination time of 8 hours. NO with an initial concentration of 107 mg/m3 was completely removed at room temperature without any reductant being necessary. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy indicated that NO is adsorbed and stored on the catalyst mainly as various coordinated nitrites and nitrates.