Laboratoire de Chimie, ENS Lyon, Université de Lyon, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07 (France).
Angew Chem Int Ed Engl. 2014 Aug 4;53(32):8316-9. doi: 10.1002/anie.201402958. Epub 2014 Jun 11.
Platinum is a prominent catalyst for a multiplicity of reactions because of its high activity and stability. As Pt nanoparticles are normally used to maximize catalyst utilization and to minimize catalyst loading, it is important to rationalize and predict catalytic activity trends in nanoparticles in simple terms, while being able to compare these trends with those of extended surfaces. The trends in the adsorption energies of small oxygen- and hydrogen-containing adsorbates on Pt nanoparticles of various sizes and on extended surfaces were analyzed through DFT calculations by making use of the generalized coordination numbers of the surface sites. This simple and predictive descriptor links the geometric arrangement of a surface to its adsorption properties. It generates linear adsorption-energy trends, captures finite-size effects, and provides more accurate descriptions than d-band centers and usual coordination numbers. Unlike electronic-structure descriptors, which require knowledge of the densities of states, it is calculated manually. Finally, it was shown that an approximate equivalence exists between generalized coordination numbers and d-band centers.
铂因其高活性和高稳定性而成为多种反应的重要催化剂。由于纳米粒子通常用于最大限度地提高催化剂的利用率并最小化催化剂的负载量，因此重要的是要以简单的术语来合理化和预测纳米粒子中的催化活性趋势，同时能够将这些趋势与扩展表面的趋势进行比较。通过使用表面位点的广义配位数，通过 DFT 计算分析了不同尺寸的 Pt 纳米粒子和扩展表面上的小含氧和含氢吸附物的吸附能趋势。这个简单而有预测性的描述符将表面的几何排列与其吸附特性联系起来。它生成线性吸附能趋势，捕捉有限尺寸效应，并提供比 d 带中心和常用配位数更准确的描述。与需要了解态密度的电子结构描述符不同，它是手动计算的。最后，证明了广义配位数和 d 带中心之间存在近似等效性。
