Daniel Silvan Dolling, Jiachen Chen, Jan-Christian Schober, Marcus Creutzburg, Arno Jeromin, Vedran Vonk, Dmitry I. Sharapa, Thomas F. Keller, Philipp N. Plessow, Heshmat Noei* and Andreas Stierle*,
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引用次数: 0
Abstract
We studied the adsorption of CO on Pd/Pt nanoparticles (NPs) with varying compositions using polarization-dependent Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) and theoretical calculations (DFT). We prepared PtPd alloy NPs via physical vapor codeposition on α-Al2O3(0001) supports. Our morphological and structural characterization by scanning electron microscopy and grazing incidence X-ray diffraction revealed well-defined, epitaxial NPs. We used CO as a probe molecule to identify the particles’ surface active sites. Polarization-dependent FT-IRRAS enabled us to distinguish CO adsorption on top and side facets of the NPs. The role of the Pd/Pt alloy ratio on CO adsorption was investigated by comparing the experimental CO stretching band frequency for different alloy arrangements to the results for pure Pd and Pt NPs. Moreover, we studied the influence of hydrogen adsorption on the NP surface composition. We determined the dependence of the IR bands on the local atomic arrangement via DFT calculations, revealing that both bulk alloy composition and neighboring atoms influence the wavenumber of the bands.
我们利用偏振相关傅立叶变换红外反射吸收光谱(FT-IRRAS)和理论计算(DFT)研究了不同成分的钯/铂纳米粒子(NPs)对一氧化碳的吸附。我们在 α-Al2O3(0001)支撑物上通过物理气相共沉积制备了铂钯合金 NPs。我们通过扫描电子显微镜和掠入射 X 射线衍射进行了形态和结构表征,发现了定义明确的外延 NPs。我们使用 CO 作为探针分子来识别颗粒的表面活性位点。偏振依赖性傅立叶变换红外光谱仪(FT-IRRAS)使我们能够区分一氧化碳在 NPs 顶面和侧面的吸附情况。通过比较不同合金排列的实验 CO 伸缩带频率与纯钯和铂 NPs 的结果,研究了钯/铂合金比例对 CO 吸附的作用。此外,我们还研究了氢吸附对 NP 表面组成的影响。我们通过 DFT 计算确定了红外谱带对局部原子排列的依赖性,结果表明块体合金成分和邻近原子都会影响谱带的波数。
期刊介绍:
ACS Nano, published monthly, serves as an international forum for comprehensive articles on nanoscience and nanotechnology research at the intersections of chemistry, biology, materials science, physics, and engineering. The journal fosters communication among scientists in these communities, facilitating collaboration, new research opportunities, and advancements through discoveries. ACS Nano covers synthesis, assembly, characterization, theory, and simulation of nanostructures, nanobiotechnology, nanofabrication, methods and tools for nanoscience and nanotechnology, and self- and directed-assembly. Alongside original research articles, it offers thorough reviews, perspectives on cutting-edge research, and discussions envisioning the future of nanoscience and nanotechnology.