SusChEM: Energies of Adsorbed Catalytic Intermediates on Transition Metal Surfaces

在这个由化学催化项目资助的项目中，华盛顿大学的Charles T. Campbell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。这项工作包括对燃料电池或环境应用中经常遇到的小群原子的控制吸附，这些原子通常被用作催化剂的金属表面，如铜、镍和铂。当这些通常只含有碳、氢和氧的小簇原子吸附到金属表面时，就形成了化学键。研究人员正在使用一种众所周知的称为量热法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，供计算科学家使用，他们将对这些表面或其他环境中可能发生的化学反应进行模拟。因此，通过创建其他科学家可以利用和使用的公共资源，这项工作正在产生广泛的影响。它提供了设计更好的催化剂所需的基本知识，从而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，从而产生了进一步广泛的影响。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。这个项目的重点是对吸附在单晶Ni， Cu和Pt表面上的明确的催化反应中间体（特别是-OH， -OCH3, -OOCH， -CH3和-CH）的能量进行量热测量。这些代表了催化反应机制中最常见的五种吸附质，当它们结合在一起时，它们提供了在能源相关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制和结构-反应性相关性的能量基础。Campbell正在与斯坦福大学的Jens Nørskov合作，将这些测量结果与先前的文献结合起来，创建一个可靠的吸附能基准数据库。该数据库将帮助理论学家开发计算表面反应能量学的计算方法，提高能量精度。虽然具有周期边界条件的密度泛函理论（DFT）在催化研究中取得了巨大的成功，但该方法在吸附中间体的相对能量上仍然存在较大的误差。该数据库的建设促进了理论和计算化学社区正在进行的努力，以提高这些快速计算方法的能量准确性。它还帮助其他研究人员寻求更充分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.