活性炭为载体加氢脱氮催化剂的研究

STUDY OF HYDRODENIGROGEN CATALYST OF Ni,MO SUPPORTED ON ACTIVATED CARBON

Ｍｏ／Ｃ、Ｎｉ／Ｃ和Ｎｉ－Ｍｏ／Ｃ催化剂吡啶加氢脱氮研究表明，Ｍｏ／Ｃ催化剂在Ｍｏ含量小于３．６５％时，随着Ｍｏ含量的增加，脱氮活性增加，其后趋于稳定。Ｎｉ／Ｃ催化剂也具有加氢脱氮活性，在Ｎｉ含量为５％左右达到最大值。Ｎｉ－Ｍｏ／Ｃ催化剂只有在Ｍ和Ｍｏ相互匹配时才具有较高的活性。ＸＰＳ的研究表明，硫化后Ｎｉ－Ｍｏ／Ｃ催化剂中Ｍｏ主要是以ＭｏＳ＿２的形态存在的；Ｎｉ是以ＮｉＳ和Ｎｉ＿３Ｓ＿２的混合态存在的；硫主要是以Ｓ￣（２－）的形态存在的，也含有一些（Ｓ－Ｓ）￣（２－）的形态。ＳＥＭ的研究表明，Ｍｏ／Ｃ催化剂中的活性组分ＭｏＳ＿２在载体上呈大小不等的三维微晶，微晶的总体分布均匀；Ｎｉ在Ｎｉ／Ｃ催化剂载体上的分布不均匀；Ｎｉ－Ｍｏ／Ｃ催化剂中的活性组分在载体上的总体分布均匀，微晶上存在许多纤维状的形态，它和Ｍｏ／Ｃ、Ｎｉ／Ｃ催化剂有明显的差别。

A series of Ni , Mo and Ni-Mo hydrodenitrogen(HDN ) catalysts supported on activated carbon were prepared by using incipient wetness impregnation method. The HDN activity of Ni/C, Mo/Cand Ni-Mo/C catalysts after sulfidation was measured. TheHDN activity of Mo/C catalyst increases with the increasing of the Mo content when Mocontent is lower than 3. 65 wt%, After that it maintains constant. The Ni/Ccatalyst aloneexhibits HDN activity, but it is lower than that of Mo/Cand Ni-Mo/Ccatalysts。 The Ni-Mo/Ccatalyst exhibits very high HDN activity when Ni and Mo are compatible. XPS analy-sis whows that Ni-Mo/C contains principally MoS_2and NiS-Ni_3S_2 on the surface after sul-fidation, and the low-valence-state sulphur,e.g.,(S-S)￣(2-)in it. SEM analysis showsthat the crystalline size of the MoS_2 in Mo/C catalyst covers a wide range but are well-dis-persed on the average. Ni sulfide particles in Ni/C catalyst are not homogeneously distribu-ed. Ni and Mo active phase in Ni-Mo/C catalyst is also well-dispersed on the average, butit has many fiber-like structures, this is different from Mo/Cand Ni/Ccatalysts.