In this study, we demonstrate that phosphorus-modification of Pt/Al2O3 leads to sinter-stable catalysts with improved activity in the dehydrogenation of perhydro benzyltoluene, an attractive liquid organic hydrogen carrier. TEM images show that platinum nanoparticles are stabilized to a size below 1 nm by the P-modification procedure, while unmodified counterparts show considerable sintering after reduction at 600 °C. The modification procedure starts by a simple impregnation of Pt/Al2O3 with H3PO3, followed by a high temperature treatment above 550 °C. It is crucial to adjust the right P:Pt ratio to reach stabilization of all platinum nanoparticles and thereby high catalytic surface areas. In our dehydrogenation studies, a catalyst with the optimal molar P:Pt ratio of 1.8 shows a 18 % higher activity compared to the unmodified sample. Even after treating the catalyst at temperatures up to 900 °C, this activity boost remains. XPS and XRD measurements prove that Pt stays in its reduced elemental state, also after P-modification, which is essential for a good dehydrogenation activity. The phosphorus species act as an anchor for the Pt particles on the Al2O3 surface, reducing their mobility and preserving small nanoparticles.

中文翻译：

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Pt/Al2O3 催化剂的磷改性提高分散性和环烷烃脱氢活性


在这项研究中，我们证明 Pt/Al2O3 的磷改性可产生烧结稳定的催化剂，并在全氢苄基甲苯（一种有吸引力的液态有机氢载体）脱氢中提高活性。 TEM 图像显示，通过 P 改性程序，铂纳米粒子的尺寸稳定在 1 nm 以下，而未改性的对应物在 600 °C 还原后显示出相当大的烧结。改性过程首先用 H3PO3 简单浸渍 Pt/Al2O3，然后进行 550 °C 以上的高温处理。调整正确的 P:Pt 比例对于实现所有铂纳米粒子的稳定并从而获得高催化表面积至关重要。在我们的脱氢研究中，最佳 P:Pt 摩尔比为 1.8 的催化剂与未改性的样品相比，其活性提高了 18%。即使在高达 900 °C 的温度下处理催化剂后，这种活性提升仍然存在。 XPS 和 XRD 测量证明，Pt 在 P 改性后仍保持还原元素状态，这对于良好的脱氢活性至关重要。磷物质充当 Al2O3 表面上 Pt 颗粒的锚定物，降低其流动性并保留小纳米颗粒。