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采用不同的沉积法制备了氧化铌(Nb_2O_5)负载的金纳米粒子催化剂,即沉积-沉淀(DP)法、尿素辅助的DP法、沉积-还原(DR)法和一步法制备了1 wt%Au/Nb_2O_5催化剂.在众多类型Nb_2O_5(包括商业Nb_2O_5)中,采用水热法制备的层间型Nb_2O_5(Nb_2O_5(HT))最适合用作载体.结果表明,较大比表面积的Nb_2O_5(HT)使得金以纳米颗粒形式分散于其上.在优化的条件下,以DP和DR法沉积于Nb_2O_5(HT)上的金纳米粒子平均粒径为5 nm.采用DR法制备的Au/Nb_2O_5(HT)催化剂上CO转化率为50%时的温度为73 oC.不沉积金的条件下,即使在250 oC,Nb_2O_5(HT)对CO氧化反应也没有催化活性.因此,金的沉积对活性的促进作用非常明显.该简易Au/Nb_2O_5催化剂将金催化剂的类型扩展到酸性载体,这将增加新的应用.
Gold nanoparticles supported on niobium oxide (Nb 2 O 5) were prepared by different deposition methods, namely deposition-precipitation (DP) method, urea-assisted DP method and deposition-reduction method / Nb 2 O 5 catalyst.The intermetallic Nb 2 O 5 (Nb 2 O 5) (HT 2) prepared by hydrothermal method is the most suitable carrier for many types of Nb 2 O 5 (including commercial Nb 2 O 5) .The results show that Nb 2 O 5 (HT) Au was dispersed on the nanoparticles as nanoparticles.Under the optimum conditions, the average particle size of gold nanoparticles deposited on Nb 2 O 5 (HT) by DP and DR methods was 5 nm.The Au / Nb 2 O 5 (HT) The temperature at which the CO conversion was 50% on the catalyst was 73 ° C. Nb 2 O 5 (HT) had no catalytic activity on the CO oxidation even at 250 o C. The deposition of gold promoted the activity It is clear that this simple Au / Nb 2 O 5 catalyst extends the type of gold catalyst to acidic supports, which will add new applications.