工业Pd-Ni合金捕集网的表面状态研究

Surface State of Industrial Pd-Ni Alloy Catchment Gauzes

在制备硝酸的氨氧化装置中，Ｐｄ－Ｎｉ合金作为捕集网用来回收铂，化学分析、电子探针微区分析和Ｘ射线光电子能谱被用来测定使用不同时间的网试样的成份和表面状态变化与分布。Ｐｔ／Ｐｄ和Ｒｈ／Ｐｄ比值与试样所在位置与运行时间有关。在捕集网表面上主组元的化学状态是Ｐｄ°、ＰｄＯ；Ｐｔ°、ＰｔＯａｄｓ、ＰｔＯ２；Ｒｈ２Ｏ３；Ｎｉ°、ＮｉＯ。发现各层网表面上Ｐｔ／Ｐｄ比值与这些表面上ＰｄＯ浓度成反比。

Pd-Ni alloys were used as catchment gauzes to recovery platinum in ammonia oxidation apparatus of nitric acid plants.In present paper,the various methods including chemical analysis,electron probe microarea analysis and X-ray photoelectron spectroscopy were used to determine the change of compositions,the Pt/Pd and Rh/Pd ratios,and the chemical state on the surface.The chemical species of main components,Pd,PdO,Pt,PtOads,PtO2,Rh2O3,Niand NiO,were found on the surfaces with different concentration and distribution depending on the position and the duration of run.It was found also that the Pt/Pd ratios on various surfaces are inversely proportional to the concentration of PdO formed on the surfaces.A new mechanism of platinum recovery was discussed.