Au/SnO_2的制备及其低温CO氧化催化性能

Preparation and Catalytic Activity of Au/SnO_2 for Low-temperature CO Oxidation

用沉积-沉淀法制备了不同金含量的Au/SnO2催化剂.采用XRD和UV—Vis等手段对催化剂样品进行了表征并考察了沉积溶液的pH值、金的负载量、焙烧温度和气氛等对Au/snO2催化CO氧化活性的的影响,结果表明:当沉积溶液的pH=9～10时,所制得的金属金的平均粒径最小;随着金的负载量的增大,金属金的粒径增大,Au/SnO2的催化活性降低;在所研究的条件下,Au/snO2前驱体在空气中473K下焙烧4h,得到的催化剂活性最高;在氢气中373 K下处理2h的Au/SnO2的催化活性在所有样品中是最高的.

Three Au/SnO2 catalysts with different gold loading were prepared via deposition-precipitation method, and characterized by XRD and UV-Vis. The effects of pH of deposition solution, Au loading and pretreatment condition on the catalytic activity of Au/SnO2 catalysts for low-temperature CO oxidation were investigated. The results showed that (1) the mean Au particle size of Au/SnO2 catalyst prepared at pH = 9 similar to 10 deposition condition was the smallest among the samples obtained at different deposition pH; (2) the catalytic activity decreased with the increase of Au loading; (3) among the 2% Au/SnO2 catalyst samples calcined at different temperatures in air for 4 h, the catalytic activity of the sample calcined at 473 K was the highest; (4) the catalyst samples pretreated at low temperature in H-2 exhibited higher activity, and the activity of the sample obtained at 373 K for 2 h was the highest among all Au/SnO2 samples in this work.