溶剂化金属原子浸渍法制备的Ni－Ag／γ－Al_2O_3催化剂的结构表征

STRUCTURAL CHARACTERIZATION OF Ni Ag/ γ Al 2O 3 CATALYSTS PREPARED VIA SOLVATED METAL ATOM IMPREGNATION METHOD

应用溶剂化金属原子浸渍（ＳＭＡＩ）法和普通浸渍（ＣＩ）法制备了三种不同摩尔比的γ－Ａｌ２Ｏ３负载Ｎｉ－Ａｇ双金属催化剂。ＸＲＤ和磁测定结果表明ＳＭＡＩ催化剂中Ｎｉ和Ａｇ的粒度均小于金属含量相同的ＣＩ催化剂，ＳＭＡＩ催化剂中Ｎｉ和Ａｇ未形成合金，而ＣＩ催化剂中Ｎｉ和Ａｇ形成了合金。ＳＭＡＩ和ＣＩ催化剂都具有超顺磁性。ＸＰＳ测定结果表明ＳＭＡＩ催化剂中零价Ｎｉ和Ａｇ的含量均高于ＣＩ催化剂。ＳＭＡＩ催化剂Ｎｉ在表面含量高于体相，Ｎｉ在表面富集。

The Solvated Metal Atom Impregnation (SMAI) and Conventional Impregnation (CI) methods were used to prepare different mole ratio bimetallic catalysts supported on γ Al 2O 3. The results of XRD and magnetic measurements showed that the Ni and Ag particle sizes of SMAI catalysts were smaller than those of CI catalysts with the same metal contents. Ni Ag alloy was formed in CI catalysts but not formed in SMAI catalysts. Both SMAI and CI catalysts had superparamagnetism. The results of XPS measurement showed that the contents of zero state metallic Ni and Ag of SMAI catalysts were higher than those of CI catalysts. The Ni concentration on the surface was higher in the bulk for SMAI catalysts, i.e.Ni was enriched on the surface. whereas the Ni concentration on the surface was essentially the same as in the bulk for CI catalysts.