The modification of Pt surfaces with organic compounds like melamine enhances oxygen reduction reaction activity and catalyst durability. Through first-principles free energy calculations utilizing thermodynamic integration and finite-temperature molecular dynamics, enhanced by machine learning force fields for efficient sampling of nanosecond-scale interfacial water fluctuations and incorporating corrections to accurately reproduce first-principles free energies, we demonstrate that melamine destabilizes OH adsorbates, facilitating their removal and enhancing catalytic activity. Unlike alloys, where OH destabilization is driven by changes in electronic structure and surface strain, melamine disrupts hydrogen bonding between OH and interfacial water. Structural and vibrational analyses reveal that melamine alters the water solvation structure, which is evident in modified radial distribution functions and a blue shift in the O–H stretching vibrations. These findings indicate that manipulating interfacial solvation with organic compounds could be a promising approach to enhance catalytic activity without compromising durability.

中文翻译：

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三聚氰胺驱动的溶剂化效应促进了铂催化剂上的氧还原：机器学习辅助的自由能计算


用三聚氰胺等有机化合物对 Pt 表面进行改性可增强氧还原反应活性和催化剂耐久性。通过利用热力学积分和有限温度分子动力学的第一性原理自由能计算，通过机器学习力场对纳秒级界面水波动进行有效采样并结合校正以准确再现第一性原理自由能，我们证明了三聚氰胺会破坏 OH 吸附物的稳定性，促进它们的去除并增强催化活性。与合金不同，氢氧化氢不稳定是由电子结构和表面应变的变化驱动的，而三聚氰胺会破坏氢氧化氢和界面水之间的氢键。结构和振动分析表明，三聚氰胺会改变水溶剂化结构，这在改进的径向分布函数和 O-H 拉伸振动的蓝移中很明显。这些发现表明，用有机化合物操纵界面溶剂化可能是一种在不影响耐久性的情况下提高催化活性的有前途的方法。