Yang Guoju, Akhade Sneha A, Chen Xi, Liu Yue, Lee Mal-Soon, Glezakou Vassiliki-Alexandra, Rousseau Roger, Lercher Johannes A
Department of Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany.
College of Chemistry and International Center of Future Science, Jilin University, Qianjin Str. 2699, 130012, Changchun, P. R. China.
Angew Chem Int Ed Engl. 2019 Mar 11;58(11):3527-3532. doi: 10.1002/anie.201813958. Epub 2019 Jan 29.
The thermodynamic state of H adsorbed on Pt in the aqueous phase was determined by kinetic analysis of H reacting with D O to HDO, HD, and D , and by DFT-based ab initio molecular dynamics simulations of H adsorption on Pt(111), Pt(110), and Pt nanoparticles. Dissociative adsorption of H on Pt is significantly weakened in the aqueous phase compared to adsorption at gas-solid interfaces. Water destabilizes the adsorbed H atoms, decreasing the heat of adsorption by 19-22 kJ while inducing an additional entropy loss of 50-70 J K . Upon dissociative adsorption of H , the average distance of water from the Pt surface increases and the liquid adopts a structure that is more ordered than before close to the Pt surface, which limits the translation mobility of the adsorbed H atoms. The presence of hydrated hydronium ions next to the Pt surface further lowers the H-Pt bond strength.
通过对氢与重水反应生成HDO、HD和D的动力学分析，以及基于密度泛函理论（DFT）的氢在Pt(111)、Pt(110)和Pt纳米颗粒上吸附的从头算分子动力学模拟，确定了水相中吸附在Pt上的氢的热力学状态。与气固界面吸附相比，氢在水相中在Pt上的解离吸附显著减弱。水使吸附的氢原子不稳定，吸附热降低19 - 22 kJ/mol，同时导致额外的50 - 70 J/(mol·K)的熵损失。氢发生解离吸附后，水与Pt表面的平均距离增加，并且液体在靠近Pt表面处采用比之前更有序的结构，这限制了吸附氢原子的平移迁移率。Pt表面附近水合氢离子的存在进一步降低了H - Pt键强度。
