HPO法合成羟胺催化剂Pd+Pt/C的制备研究

Preparation of Pd-Pt/C Catalyst for Synthesis of Hydroxylamine Phosphate

本文对NO3-加氢还原制羟胺的Pd＋Pt／C催化剂进行了研究，考察了载体活性炭来源、预处理条件、Pt添加量、助剂种类和用量等因素对催化剂性能的影响。研究表明选择大、中孔比例高（≥70％）的活性炭做载体，并进行适当的表面处理，可改善活性组份Pd、Pt的分散度和提高对产物羟胺的选择性。添加一定量Pt（≤20％）可显著提高催化剂活性。XRD物相分析表明还原反应活性中心可能是Pd－Pt合金。实验还确定了GeO2。为合适的助剂，其最佳添加范围为2-4mgGeO2／g·cat。

The preparation of Pd+Pt/C catalyst for nitrate reduction to hydroxylamine was studied. Effect ofthe sources of activated carbon as support, pretreatrnent conditions, addition of Pt and the type andamount of promoters on the catalyst performance was Investigated. The study showed that an activatedcarbon with suitable pore size distribution (≥70 % macroporosity) and proper pretreatment may improvethe dispersion of Pd and Pt on activated carbon and enhance the selectivity to hydroxylamine. Additionof Pt (≤20% ) increases the catalytic activity remarkably. XRD measurements suggested that a Pd Ptalloy may be the active site of the reduction process. Experimental results also pointed out that GeO2 isa better promoter with the addition range of 2～4 mg Geo2/g·cat.