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采用Ｘ射线吸收精细结构（ＸＡＦＳ）、Ｘ射线衍射（ＸＲＤ）、差热分析（ＤＴＡ）３种方法研究化学还原法制备的ＮｉＢ超细非晶态合金在退火过程中的结构变化及结构与催化性能的关系．ＸＲＤ和ＸＡＦＳ结果表明， ＮｉＢ超细非晶态合金的退火晶化过程分两步进行，在 ３２５℃的退火温度下， ＮｉＢ超细非晶态合金晶化生成纳米晶 Ｎｉ３Ｂ亚稳物相；在 ３８０℃或更高的退火温度下，绝大部分Ｎｉ３Ｂ进一步晶化分解生成金属Ｎｉ物相，其产物中Ｎｉ的局域环境结构与金属Ｎｉ箔的基本一致．发现纳米晶Ｎｉ３Ｂ比超细Ｎｉ－Ｂ非晶态合金或晶态金属Ｎｉ粉末有更好的苯加氢催化活性，表明其催化反应活性中心由具有适当几何构型的Ｎｉ与Ｂ原子组成．
The structure and catalytic properties of NiB ultrafine amorphous alloys prepared by chemical reduction during annealing were investigated by X-ray absorption fine structure (XAFS), X-ray diffraction (XRD) and differential thermal analysis (DTA) The relationship between performance. XRD and XAFS results show that the annealing crystallization process of NiB ultrafine amorphous alloy is carried out in two steps. At the annealing temperature of 325 ℃, NiB superfine amorphous alloy is crystallized to form nanocrystalline Ni3B metastable phase. At the annealing temperature of 380 ℃ or higher, most of the Ni3B crystallizes and decomposes to form the metal Ni phase. The local environment structure of Ni in the product is basically the same as that of the metal Ni foil. It was found that nanocrystalline Ni3B has better benzene hydrogenation catalytic activity than that of ultrafine Ni-B amorphous alloy or crystalline metallic Ni powder, indicating that the catalytic active center consists of Ni and B atoms with the proper geometry.