The adsorption of hexachloroplatinic acid on Sn-impregnated γ-alumina support in the presence of the competitive chloride ion, as a step in preparation of multi-metallic Pt-based catalyst (such as Pt–Sn/Al₂O₃), was studied. The transient adsorption data were obtained by studying the impregnation of Sn/Al₂O₃ with H₂PtCl₆ in an external recycle packed-bed impregnation system. The effect of important parameters such as pH of the impregnating solution, circulation flow rate, and height/diameter ratio of support bed on competitive adsorption was studied. It was observed that upon increasing pH and decreasing circulation rate, the rate of Pt adsorption as well as axial non-uniformity along the bed was increased. On the other hand, a time lag was observed in bulk adsorbate concentration in certain runs which was attributed to deviation from well-mixed contacting pattern being necessary for a uniform catalyst product. This could be minimized by increasing the recycling flow rates and using appropriate amounts of competitive ion concentration.

中文翻译：

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间歇浸渍体系有效参数的实验研究：以Pt-Sn / Al 2 O 3催化剂为例

研究了在竞争氯离子存在下六氯铂酸在锡浸渍的γ-氧化铝载体上的吸附，以此作为制备多金属Pt基催化剂（如Pt–Sn / Al ₂ O ₃）的步骤。通过研究H ₂ PtCl ₆对Sn / Al ₂ O ₃的浸渍获得瞬时吸附数据。在外部循环填充床浸渍系统中。研究了浸渍液的pH值，循环流量，支撑床高径比等重要参数对竞争性吸附的影响。观察到，随着pH值的增加和循环速率的降低，Pt的吸附速率以及沿床的轴向不均匀性都增加了。另一方面，在某些运行中观察到总吸附物浓度存在时间滞后，这是由于偏离均匀混合的接触模式对于均匀催化剂产物所必需的。可以通过提高循环流速和使用适量的竞争性离子浓度来最大程度地减少这种情况。