Basso Letícia F, Vanzan Mirko, Prati Laura, Rigo Vagner A, Baletto Francesca
Department of Physics, University of Milan, 20133 Milan, Italy.
Department of Chemistry, University of Milan, 20133 Milan, Italy.
J Phys Chem C Nanomater Interfaces. 2025 Apr 24;129(24):10854-10865. doi: 10.1021/acs.jpcc.4c08091. eCollection 2025 Jun 19.
After an accurate mapping of the available sites on Rh and three different RhAu nanoalloys (where = 20, 36, or 52), the CO adsorption properties are obtained using density functional theory (DFT) at the PBE functional level, incorporating the Hubbard correction (PBE + ). The values are selected to reproduce the correct adsorption trend and consistent binding of CO on Rh(111) in order to align with experimental measurements. The stabilization of the top adsorption site of CO, regarding the hollow one, is enhanced on the Rh surface, compared to the Rh(111) surface. Our findings indicate that the strength of CO adsorption on small AuRh nanoparticles can be effectively tuned by varying their morphology and composition. The energy landscape of the Rh-based nanoalloys is relatively flat, with the adsorption energies at all sites varying within 0.3 eV, similar to the trend observed for Rh(111), although Rh sites in the nanoalloys generally bind CO more strongly. Adding Au shortens the CO-Rh bond, and sites with a mixed chemical environment result in instability. The presence of Rh enables Au-sites to bind CO twice as strongly as in Au(111).
在精确绘制Rh上的可用位点以及三种不同的RhAu纳米合金（其中 = 20、36或52）之后，使用密度泛函理论（DFT）在PBE泛函水平上并结合哈伯德校正（PBE + ）来获得CO的吸附特性。选择这些 值以重现正确的吸附趋势以及CO在Rh(111)上的一致结合，以便与实验测量结果相符。与Rh(111)表面相比，在Rh表面上，CO在顶部位点相对于中空位点的稳定性增强。我们的研究结果表明，通过改变小尺寸AuRh纳米颗粒的形态和组成，可以有效地调节CO在其上的吸附强度。基于Rh的纳米合金的能量分布相对平坦，所有位点的吸附能在0.3 eV范围内变化，这与在Rh(111)上观察到的趋势相似，尽管纳米合金中的Rh位点通常与CO的结合更强。添加Au会缩短CO-Rh键，并且具有混合化学环境的位点会导致不稳定性。Rh的存在使Au位点结合CO的强度是Au(111)中的两倍。
