在[PtAu(PPh)]-H[PMoO]固体中对CO和H在Pt上吸附的QXAFS研究

QXAFS study of CO and H adsorption on Pt in [PtAu(PPh)]-H[PMoO] solid.

作者信息

Matsuyama Tomoki, Suzuki Taishi, Oba Yuto, Kikkawa Soichi, Uchida Sayaka, Ohyama Junya, Higashi Kotaro, Kaneko Takuma, Kato Kazuo, Nitta Kiyofumi, Uruga Tomoya, Hatada Keisuke, Yoshikawa Kazuki, Heilmaier Amelie, Suzuki Kosuke, Yonesato Kentaro, Yamaguchi Kazuya, Nakatani Naoki, Kawasoko Hideyuki, Yamazoe Seiji

机构信息

Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-osawa, Hachioji-shi, Tokyo 192-0397, Japan.

Department of Basic Science, School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.

出版信息

Nanoscale. 2025 Jan 29;17(5):2480-2487. doi: 10.1039/d4nr03785e.

DOI:10.1039/d4nr03785e

PMID:39611297

Abstract

The adsorption behaviors of H and CO molecules in crown-motif [PtAu(PPh)]-H[PMoO] (PtAu8-PMo12) solids were investigated by quick-scan X-ray absorption fine structure (QXAFS) measurements with a time resolution of 0.1 s. The electronic state of Pt in PtAu8-PMo12 was drastically changed by the adsorption of H and CO molecules because of the formation of Pt-H/Pt-CO interactions. H was adsorbed more rapidly (<0.5 s) on Pt than CO (∼2.5 s) and showed reversible adsorption/desorption behavior on Pt atoms in PtAu8-PMo12. The rapid adsorption of H is due to the fast diffusion of H, which has a smaller kinetic diameter than CO, in the narrow channels between the closed voids in PtAu8-PMo12. Meanwhile, CO was irreversibly adsorbed on Pt, resulting in structural isomerization to the stable "chalice-motif" PtAu8, which was determined by XAFS analysis and density functional theory calculations. Structural isomerization was involved by pushing ligands aside to make space for CO adsorption as the void size near Pt in the crown-motif PtAu8-PMo12 was narrower than the kinetic diameter of CO.

摘要

通过时间分辨率为0.1 s的快速扫描X射线吸收精细结构（QXAFS）测量，研究了冠型[PtAu(PPh)]-H[PMoO]（PtAu8-PMo12）固体中H和CO分子的吸附行为。由于形成了Pt-H/Pt-CO相互作用，PtAu8-PMo12中Pt的电子态因H和CO分子的吸附而发生了显著变化。H在Pt上的吸附速度比CO（约2.5 s）更快（<0.5 s），并且在PtAu8-PMo12中的Pt原子上表现出可逆的吸附/解吸行为。H的快速吸附是由于H的快速扩散，H的动力学直径比CO小，在PtAu8-PMo12中封闭空隙之间的狭窄通道中扩散。同时，CO不可逆地吸附在Pt上，导致结构异构化为稳定的“圣杯型”PtAu8，这是通过XAFS分析和密度泛函理论计算确定的。由于冠型PtAu8-PMo12中Pt附近的空隙尺寸比CO的动力学直径窄，通过将配体推开以腾出空间进行CO吸附，从而涉及结构异构化。