Sideri Ioanna K, Arenal Raul, Tagmatarchis Nikos
National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute 48 Vassileos Constantinou Avenue 11635 Athens Greece
Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC-U. de Zaragoza 50009 Zaragoza Spain.
Nanoscale Adv. 2025 Jun 4;7(14):4469-4479. doi: 10.1039/d5na00281h. eCollection 2025 Jul 10.
Single-walled carbon nanotubes (SWCNTs) have been widely employed as electrocatalysts due to their exceptional mechanical strength and electronic properties, despite lacking intrinsic catalytic centers. Current research efforts focus on enhancing their catalytic activity by modifying them with organometallic chelate complexes, to achieve controlled molecular-level structuring and improved performance in Proton Exchange Membrane Fuel Cells (PEMFCs). While the mechanistic understanding of their electrocatalytic behavior in relation to molecular structure remains in its early stages, it offers valuable insights for the development of efficient electrocatalysts. In this study, SWCNTs were stepwise chemically modified with terpyridine ligands both in the absence of metal and in the presence of ruthenium (Ru) in two different oxidation states. The resulting SWCNT-based nanomaterials were characterized using Raman, UV-Vis, XPS and energy-dispersive X-ray spectroscopy (EDS) coupled with transmission electron microscopy (TEM) imaging, while the degree of functionalization was assessed through thermogravimetric analysis (TGA). A comprehensive electrocatalytic investigation demonstrated how covalent modification with Ru and Ru terpyridine complexes influences the mechanistic pathway of the oxygen reduction reaction (ORR). This comparative analysis underscores the critical role of the first coordination sphere of precious metals in both the thermodynamics and kinetics of ORR, when anchored onto carbon nanomaterial lattices, providing valuable insights for the nanostructured design of efficient carbon-based electrocatalysts.
单壁碳纳米管（SWCNTs）因其出色的机械强度和电子性能而被广泛用作电催化剂，尽管其缺乏内在的催化中心。当前的研究工作集中在通过用有机金属螯合物对其进行修饰来提高其催化活性，以实现质子交换膜燃料电池（PEMFCs）中可控的分子水平结构和性能提升。虽然关于其电催化行为与分子结构关系的机理理解仍处于早期阶段，但它为高效电催化剂的开发提供了有价值的见解。在本研究中，单壁碳纳米管在无金属和存在两种不同氧化态的钌（Ru）的情况下，用三联吡啶配体进行逐步化学修饰。使用拉曼光谱、紫外可见光谱、X射线光电子能谱（XPS）和能量色散X射线光谱（EDS）结合透射电子显微镜（TEM）成像对所得的基于单壁碳纳米管的纳米材料进行表征，同时通过热重分析（TGA）评估功能化程度。全面的电催化研究表明，用钌和钌三联吡啶配合物进行共价修饰如何影响氧还原反应（ORR）的机理途径。这种比较分析强调了贵金属的第一配位层在锚定到碳纳米材料晶格上时，在氧还原反应的热力学和动力学中的关键作用，为高效碳基电催化剂的纳米结构设计提供了有价值的见解。
