(631e) How Dry Should Dry Impregnation be?

Both in the lab and at commercial scale, dry impregnation (DI), and similar pore filling techniques, are by far the most commonly used methods for supported metal catalyst preparation. Despite the simplicity of DI, severe drawbacks arise from uneven distribution of metal post drying and reduction. It is known from experience that metal enrichment occurs at drying surfaces, leading to uneven loading and varying metal particle sizes within a bulk material. In this study, it is shown that the simplicity of the DI method can be preserved, but distribution of metal improved by altering a single parameter, volume of impregnating solution. By decreasing the volume of impregnating solution, it is shown that a more even distribution of metal within the bulk material is obtained post drying, and that a smaller, and tighter distribution of metal particles are obtained, post drying and reduction.