The support effect and metal particle size effect, which are often intertwined, are two critical factors influencing the activity of a supported metal catalyst. To clarify each effect on the activity of carbon-supported Pt catalysts, a series of Pt/C catalysts were elaborately prepared by adopting two carbon materials with distinct microstructures—that is, carbon nanofibers (CNFs) vs carbon nanotubes (CNTs)—and by altering the Pt particle size from 1 to 9 nm on each support. The catalytic activity was assessed during the dehydrogenation of decalin to release hydrogen. Molecular dynamics simulations based on reactive force field and density functional theoretical calculations were employed in combination with catalyst characterization techniques. Significant differences in both the geometric structure and electronic properties of Pt clusters between two kinds of Pt/C catalysts have been found, especially in the Pt particle size range smaller than 2 nm. The edge planes of CNFs can interact much more strongly with Pt atoms than the basal planes of CNTs do, hence forming a more dispersive and simultaneously more active Pt-C boundary for reaction proceeding. The carbon support effect dominates the activity divergence in the smaller size range (<2 nm), while the Pt particle size effect prevails on the catalysts with medium Pt particles (2–4 nm). Both effects can fade out with continually increasing Pt particle size.

通常相互交织的载体效应和金属粒度效应是影响负载型金属催化剂活性的两个关键因素。为了阐明每种对碳载Pt催化剂活性的影响，通过采用两种具有不同微观结构的碳材料（即碳纳米纤维（CNF）与碳纳米管（CNT）），精心制备了一系列Pt / C催化剂。将每个载体上的Pt粒径从1纳米更改为9纳米。在萘烷脱氢以释放氢的过程中评估了催化活性。基于反作用力场的分子动力学模拟和密度泛函理论计算与催化剂表征技术结合使用。已发现两种Pt / C催化剂之间Pt团簇的几何结构和电子性质均存在显着差异，尤其是在Pt粒径范围小于2 nm的情况下。CNF的边缘平面与Pt原子的相互作用要比CNT的基础平面强得多，因此形成了更分散且活性更高的Pt-C边界，可用于反应过程。碳载体效应在较小的尺寸范围（<2 nm）中支配了活性散度，而具有中等Pt颗粒（2-4 nm）的催化剂普遍存在Pt粒径效应。随着Pt颗粒尺寸的不断增加，两种效果都可能消失。CNF的边缘平面与Pt原子的相互作用要比CNT的基础平面强得多，因此形成了更分散且活性更高的Pt-C边界，可用于反应过程。碳载体效应在较小的尺寸范围（<2 nm）中支配了活性散度，而具有中等Pt颗粒（2-4 nm）的催化剂普遍存在Pt粒径效应。随着Pt颗粒尺寸的不断增加，两种效果都可能消失。CNF的边缘平面与Pt原子的相互作用要比CNT的基础平面强得多，因此形成了更分散且活性更高的Pt-C边界，可用于反应过程。碳载体效应在较小的尺寸范围（<2 nm）中支配了活性散度，而具有中等Pt颗粒（2-4 nm）的催化剂普遍存在Pt粒径效应。随着Pt颗粒尺寸的不断增加，两种效果都可能消失。