摘要
考察了沉积 沉淀法制备的Au Al2 O3催化剂在O2 存在下催化C3H6 还原NO的反应 ,并用程序升温脱附 质谱 (TPD MS)手段研究了吸附于催化剂上的NO或NO O2 的脱附性能 .结果表明 :在O2 存在的条件下 ,对于C3H6 还原NO的反应 ,1%Au Al2 O3的催化活性最高 ,可于 3 75℃左右使NO生成N2 ,转化率达 60 % .这与催化剂对所吸附NO的脱附性能密切相关 ,N2 O可能是C3H6
Au/Al_2O_3 catalyst samples with different Au loadings were prepared, through pretreatment of reduction in H_2 or calcination in air, by deposition-precipitation method. The desorption performance of NO or NO-O_2 adsorbed on Au/Al_2O_3 was investigated by temperature programmed desorption-mass spectrometry (TPD-MS) technique, and the mechanism of NO reduction was discussed. 1%Au/Al_2O_3 exhibits the highest catalytic activity, on which the conversion of NO is 60% at 375 ℃. High Au loading could lead to a lower conversion temperature, but, NO conversion decreased, and the catalysts pretreated by reduction in H_2 showed higher activity than that calcined in air. The TPD-MS results of NO adsorbed on Au/Al_2O_3 showed that N_2O was produced only on the catalyst during the process of temperature programmed desorption. The results of temperature programmed surface reaction (TPSR) showed that compared with the support Al_2O_3, the reduction temperature of NO on 1%Au/Al_2O_3 decreased to 375 ℃ from 550 ℃, which is consistent with its higher activity. According to the TPD-MS results, it is concluded that N_2O was formed in the reduction of NO with C_3H_6, which may be the intermediate in the reaction, and then N_2 formed.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第3期203-207,共5页
基金
国家自然科学基金资助项目 ( 2 98730 41)
