Santoveña-Uribe A, Maya-Cornejo J, Estevez M, Santamaria-Holek I
Unidad Multidisciplinaria de Docencia e Investigación-Juriquilla, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Juriquilla, Querétaro 76230, Mexico.
Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México (UNAM), Juriquilla, Querétaro 76230, Mexico.
Nanomaterials (Basel). 2024 Dec 7;14(23):1966. doi: 10.3390/nano14231966.
This work investigates the relationship between the mean diameter of palladium (Pd) nanoparticles and their surface energy, specifically in the context of alkaline ethanol electro-oxidation for fuel cell applications. Employing a recent generalization of the classical Laviron equation, we derive crucial parameters such as surface energy (), adsorption-desorption equilibrium constant (), and electron transfer coefficient () from linear voltammograms obtained from Pd-based nanoparticles supported on Vulcan carbon. Synthesized using two distinct methods, these nanocatalysts exhibit mean diameters ranging from 10 to 41 nm. Our results indicate that the surface energy of the Pd/C nanocatalysts spans ~ 0.5-2.5 J/m, showing a linear correlation with particle size while remaining independent of ethanol bulk concentration. The adsorption-desorption equilibrium constant varies with nanoparticle size (~0.1-6 × 10 mol) but is unaffected by ethanol concentration. Significantly, we identify an optimal mean diameter of approximately 28 nm for enhanced electrocatalytic activity, revealing critical size-dependent effects on catalytic efficiency. This research contributes to the ongoing development of cost-effective and durable fuel cell components by optimizing nanoparticle characteristics, thus advancing the performance of Pd-based catalysts in practical applications. Our findings are essential for the continued evolution of nanomaterials in fuel cell technologies, particularly in improving efficiency and reducing reliance on critical raw materials.
这项工作研究了钯（Pd）纳米颗粒的平均直径与其表面能之间的关系，特别是在用于燃料电池应用的碱性乙醇电氧化背景下。采用经典拉维龙方程的最新推广，我们从由负载在炭黑上的钯基纳米颗粒获得的线性伏安图中推导出诸如表面能（）、吸附 - 解吸平衡常数（）和电子转移系数（）等关键参数。这些纳米催化剂采用两种不同方法合成，其平均直径范围为10至41纳米。我们的结果表明，Pd/C纳米催化剂的表面能跨度约为0.5 - 2.5 J/m²，与粒径呈线性相关，而与乙醇本体浓度无关。吸附 - 解吸平衡常数随纳米颗粒尺寸变化（~0.1 - 6×10⁻⁵mol），但不受乙醇浓度影响。值得注意的是，我们确定了约28纳米的最佳平均直径以提高电催化活性，揭示了对催化效率的关键尺寸依赖性效应。这项研究通过优化纳米颗粒特性，为经济高效且耐用的燃料电池组件的持续发展做出了贡献，从而在实际应用中提高了钯基催化剂的性能。我们的发现对于燃料电池技术中纳米材料的持续发展至关重要，特别是在提高效率和减少对关键原材料的依赖方面。
