Abstract: In order to investigate the catalytic effect of H⁃ZSM⁃5 for silver⁃copper alloy nanoparticles,Ag₂Cu₁/H⁃ZSM⁃5 alloy powder catalyst was prepared and applied to low temperature NH₃⁃SCO reaction under oxygen⁃rich conditions. The results showed that the Ag₂Cu₁/H⁃ZSM⁃5 exhibited the best low⁃temperature ammonia oxidation performance, and its T₅₀ and T₉₀ were 221 and 247 °C, respectively. The results of XRD,N₂ physical adsorption and SEM showed that the MFI skeleton structure and the silver⁃copper alloy structure remained intact,and the silver⁃copper alloy nanoparticles were highly dispersed on the surface of H⁃ZSM⁃5.It could be seen from TEM results that the small size of silver⁃copper alloy nanoparticles (2~14 nm) and H⁃ZSM⁃5 surface had a strong force,which improved the dispersion of silver⁃copper alloy nanoparticles.The XPS and NH₃⁃TPD results displayed that the strong interaction between the Ag₂Cu₁ nanoparticles and the surface of H⁃ZSM⁃5 increased the amount of active oxygen on the surface of the catalyst,enhanced the adsorption of ammonia on the surface and increased the reaction rate of ammonia oxidation.

Key words: NH₃?SCO, Ag?Cu alloy, H?ZSM?5

摘要： 制备Ag₂Cu₁/H⁃ZSM⁃5合金粉末催化剂，并将其应用于富氧条件下的低温NH₃⁃SCO反应,以考察H⁃ZSM⁃5分子筛对Ag⁃Cu合金纳米颗粒催化活性的促进作用。结果表明，Ag₂Cu₁/H⁃ZSM⁃5催化剂表现出较佳的低温氨氧化性能，其T50和T90的数值分别为221、247 ℃。X射线衍射（XRD）、N₂物理吸附和扫描电子显微镜（SEM）的结果表明，Ag₂Cu₁/H⁃ZSM⁃5整体式粉末催化剂中的MFI骨架结构和Ag⁃Cu合金结构均保持完好，Ag⁃Cu合金纳米颗粒高度分散在H⁃ZSM⁃5表面。透射电子显微镜（TEM）结果证明，小尺寸的Ag⁃Cu合金纳米颗粒（2~14 nm）与H⁃ZSM⁃5分子筛表面具有较强的作用力，提高了Ag⁃Cu合金纳米颗粒的分散性。X射线光电子能谱（XPS）和NH₃⁃TPD结果表明，Ag₂Cu₁纳米颗粒和H⁃ZSM⁃5表面的强相互作用提高了催化剂表面活性氧数量，增强氨气在其表面的吸附，进而提高了氨氧化的反应速率。

关键词: NH₃?SCO, Ag?Cu合金, H?ZSM?5