Ring-hydrogenation of 4-propylphenol (4-PP) to 4-propylcyclohexanone, cis- and trans-4-propylcyclohexanols proceeded over graphite-supported palladium catalysts (Pd/G) in aqueous ethanol solution at 573 K without using external hydrogen gas. Compared to Pd/G, graphite-supported platinum (Pt/G) catalysts were active only for hydrogen production and not for the ring-hydrogenation under the same reaction conditions. We have found that the addition of platinum to palladium enhanced the cis- and trans-4-propylcyclohexanols yields. The optimum molar ratio of platinum to palladium in the Pt-Pd/G catalysts was found to be 1:2. The formation of Pt-Pd alloy sites was studied by TEM and EXAFS analyses.

中文翻译：

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Pt-Pd双金属催化剂在无外加氢的乙醇水溶液中4-丙基苯酚加氢

4-丙基苯酚 (4-PP) 环氢化成 4-丙基环己酮、顺式和反式-4-丙基环己醇在石墨负载的钯催化剂 (Pd/G) 上在 573 K 的乙醇水溶液中进行，无需使用外部氢气。与 Pd/G 相比，石墨负载的铂 (Pt/G) 催化剂仅对制氢有活性，在相同的反应条件下对环加氢没有活性。我们发现向钯中添加铂提高了顺式和反式-4-丙基环己醇的产率。发现 Pt-Pd/G 催化剂中铂与钯的最佳摩尔比为 1:2。通过 TEM 和 EXAFS 分析研究了 Pt-Pd 合金位点的形成。