SusChEM: Energies of Adsorbed Catalytic Intermediates on Transition Metal Surfaces

在这个由化学催化计划资助的项目中，查尔斯·T·华盛顿大学的坎贝尔正在开发更好的催化剂，用于大宗化学品、化肥和燃料的生产，用于污染清理和燃料燃烧。这项工作涉及控制吸附燃料电池或环境应用中经常遇到的小原子团到通常用作催化剂的金属表面，如铜，镍和铂。当这些通常只含有碳、氢和氧的小原子团吸附到金属表面时，就形成了化学键。研究人员正在使用一种称为量热法的众所周知的技术来测量这些化学键的强度。实验测量结果存储在一个数据库中，该数据库可供计算科学家使用，他们将对可能在这些表面或其他环境中发生的化学反应进行模拟。因此，这项工作通过创建一个其他科学家可以利用和使用的公开资源产生了广泛的影响。它通过提供设计更好的催化剂所需的基本理解来产生更广泛的影响，以便以更高的能源效率和更少的污染进行工业上重要的化学反应。这项工作有助于设计更好的电池和燃料电池，可以集成到太阳能和风能系统中。该项目的重点是吸附在单晶Ni，Cu和Pt表面上的明确的催化反应中间体（特别是-OH，-OCH 3，-OOCH，-CH 3和-CH）的能量的量热测量。这些代表了催化反应机制中引起的五种最常见的吸附物类别，当结合起来时，它们提供了在与能量相关的和环境催化过程中发生的许多基本步骤的能量学。这反过来又阐明了催化反应机理和结构-反应性相关性的能量基础。坎贝尔正在与斯坦福大学的Jens Nørskov合作，将联合收割机这些测量与先前的文献结合起来，以创建一个可靠的吸附能基准数据库。该数据库将帮助理论家开发计算方法，以提高能量精度来计算表面反应的能量。 虽然具有周期性边界条件的密度泛函理论（DFT）在催化研究中已经非常成功，但该方法仍然受到吸附中间体相对能量的较大误差的困扰。该数据库的建设促进了理论和计算化学界的持续努力，以提高这些快速计算方法的能量准确性。它也有助于其他研究人员更全面地了解过渡金属催化反应机制和结构活性相关性的能量基础。

In this project, funded by the Chemical Catalysis Program, Charles T. Campbell of the University of Washington is developing better catalysts for use in the production of bulk chemicals, fertilizers and fuels, for pollution cleanup, and for the combustion of fuels. The work involves the controlled adsorption of small groups of atoms that are often encountered in fuel cells or environmental applications to metal surfaces that are commonly used as catalysts, such as copper, nickel and platinum. When these small clusters of atoms, usually containing only carbon, hydrogen and oxygen, adsorb to a metal surface, a chemical bond is formed. The investigators are measuring the strength of these chemical bonds using a well-known technique known as calorimetry. The experimental measurements are stored in a database that is being made available to computational scientists who will perform simulations of chemical reactions that could potentially be occurring on these surfaces or in other settings. The work is, thus, having a broad impact through the creation of a publicly available resource that other scientists can take advantage of and use. It is having a further broad impact by providing the basic understanding needed to design better catalysts in order to carry out industrially important chemical reactions with higher energy efficiency and less pollution. This work is aiding the design of better batteries and fuel cells that can be integrated into solar and wind energy systems.This project is focused on calorimetric measurements of the energies of well-defined catalytic reaction intermediates (specifically -OH, -OCH3, -OOCH, -CH3 and -CH) adsorbed on single-crystal Ni, Cu and Pt surfaces. These represent five of the most common adsorbate classes evoked in catalytic reaction mechanisms, and when combined, they provide the energetics of many elementary steps that occur during energy-related and environmental catalysis. This, in turn, elucidates the energetic basis for reaction mechanisms and structure-reactivity correlations in catalysis. Campbell is collaborating with Jens Nørskov of Stanford University to combine these measurements with prior literature to create a benchmark database of reliable adsorption energies. This database will help theoreticians develop computational methods for calculating the energetics of reactions at surfaces with improved energy accuracy. While density functional theory (DFT) with periodic boundary conditions has been extremely successful in catalysis research, the method is still plagued by rather large errors in the relative energies of the adsorbed intermediates. The construction of this database is facilitating ongoing efforts in the theoretical and computational chemistry community to improve the energy accuracy of these fast computational methods. It is also aiding other researchers who seek to understand more fully the energetic basis for reaction mechanisms and structure-activity correlations in transition metal catalysis.