The use of dodecahydro--ethylcarbazole in hydrogen storage for liquid organic hydrogen carrier systems holds potential for achieving large-scale application. In order to investigate the relationship between dodecahydro--ethylcarbazole dehydrogenation performance and Pt particles size, a series of monometallic Pt/AlO catalysts with different Pt particles size from 0.70 nm to 5.12 nm were controlled synthesized by a simple impregnation method. The obtained catalysts are systematically characterized via XRD, Al MAS NMR, SEM-EDS, TEM, N-adsorption, CO-IR, H-TPR and NH-TPD analyses, which provide essential micro-structure of these catalysts. The dehydrogenation of dodecahydro--ethylcarbazole over Pt/AlO is a typical consecutive reaction, which follows a reaction sequence of dodecahydro--ethylcarbazole → octahydro--ethylcarbazole → tetrahydro--ethylcarbazole → -ethylcarbazole. These dehydrogenation steps are quite sensitive to the Pt particle size. Large Pt particle can greatly enhance the reaction rates in octahydro--ethylcarbazole → tetrahydro--ethylcarbazole and tetrahydro--ethylcarbazole → -ethylcarbazole steps. However, these two steps are difficult to take place in small Pt particles. The high performance of large Pt particle in dehydrogenation can be ascribed to its highly exposed (111) crystal face. The optimized catalyst Pt/γ-AlO with Pt average size of 4.63 nm demonstrated exceptional performance in dodecahydro--ethylcarbazole dehydrogenation at 180 °C and 101 kPa, and the dodecahydro--ethylcarbazole conversion of 100 %, -ethylcarbazole selectivity of 96.44 % and dehydrogenation efficiency of 98.73 % can be achieved. These results provide valuable insights for the development of efficient metal-based catalysts for liquid organic hydrogen carriers hydrogen storage system.

中文翻译：

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Pt/Al2O3 作为十二氢-N-乙基咔唑脱氢的高效催化剂


十二氢-乙基咔唑在液态有机氢载体系统储氢中的应用具有大规模应用的潜力。为了研究十二氢-乙基咔唑脱氢性能与Pt粒径的关系，通过简单的浸渍方法控制合成了一系列不同Pt粒径（0.70 nm至5.12 nm）的单金属Pt/Al2O催化剂。通过 XRD、Al MAS NMR、SEM-EDS、TEM、N-吸附、CO-IR、H-TPR 和 NH-TPD 分析对所得催化剂进行了系统表征，提供了这些催化剂的基本微观结构。十二氢-乙基咔唑在Pt/Al2O上的脱氢是典型的连续反应，其反应顺序为十二氢-乙基咔唑→八氢-乙基咔唑→四氢-乙基咔唑→乙基咔唑。这些脱氢步骤对 Pt 颗粒尺寸非常敏感。大的 Pt 颗粒可以大大提高八氢-乙基咔唑→四氢-乙基咔唑和四氢-乙基咔唑→-乙基咔唑步骤的反应速率。然而，这两个步骤在小铂颗粒中很难发生。大 Pt 颗粒在脱氢过程中的高性能可归因于其高度暴露的 (111) 晶面。优化后的催化剂Pt/γ-Al2O（Pt平均粒径为4.63 nm）在180 °C和101 kPa的十二氢-乙基咔唑脱氢反应中表现出优异的性能，十二氢-乙基咔唑转化率为100%，β-乙基咔唑选择性为96.44%，脱氢效率可达98.73%。 这些结果为开发用于液态有机氢载体储氢系统的高效金属基催化剂提供了宝贵的见解。