SusChEM: Energies of Adsorbed Catalytic Intermediates on Transition Metal Surfaces: Experimental Benchmarks for Computational Catalysis Research

催化剂是为所需化学反应提供更有效和选择性途径的化学品。 过渡金属催化剂特别适用于生产散装化学品和燃料，以及更清洁的燃料燃烧和污染清除。对于这些固体催化剂，催化剂表面的金属以适当的强度（或“键能”）结合反应化学品，使它们能够化学转化为所需的产物。 如果结合太紧，则产物不会解吸，而是仍然附着在催化剂表面上。 如果结合太弱，反应物将无法吸附，也无法与之发生催化反应。提高此类催化剂的能量对于生产和使用具有更高能效和更少污染的化学品和燃料至关重要，这是未来可持续生活所需的。 改进催化剂的关键是找到其表面以最佳键能结合反应化学品的材料。 原则上，这可以通过用计算机求解量子力学（物理学的一个分支）方程来实现。 不幸的是，数学是非常困难的，所以即使是最快的计算机也必须进行数学近似，才能在合理的时间内解出方程。 一些键能的实验测量需要与计算机结果进行比较，以评估这些近似值是否会导致不正确的键能。 在这个项目中，查尔斯·T。坎贝尔正在测量与过渡金属表面结合的选定化学物质的键能，这些化学物质经过精心挑选，能够开发新的量子力学方法，更准确地预测这些能量，并提高对催化剂作用的基本理解。提高这种快速计算的能量准确性在多相催化领域具有变革性，使基于计算机的更好催化剂材料预测具有更高的可靠性。这项研究还为众多年轻学生，科学家和工程师提供了强大的跨学科，研究综合教育，他们获得了最先进的测量仪器及其设计的实践经验。 坎贝尔博士通过他频繁的公开演讲，众多的编辑和咨询委员会成员，以及对大学和外部科学教育倡议的服务，参与了广泛的外展活动，以更广泛的社区。后过渡金属催化剂和电催化剂用于大宗化学品和燃料的生产，用于清洁燃料燃烧和污染清除。改进这些催化剂对于生产和使用具有更高能效和更少污染的化学品和燃料至关重要，这是可持续生活所需的。 在化学部化学催化计划的资助下，查尔斯·T·华盛顿大学的坎贝尔正在测量发生在后过渡金属表面上的选定的基本化学反应的能量，精心选择，以便能够开发新的理论方法，更准确地预测这种能量。 这反过来又提高了对催化机理的基本理解，并促进了更好的催化剂的设计。坎贝尔博士的量热测量在世界其他地方无法以同样的精度进行，正在扩大吸附催化中间体的可靠实验能量的数据库，这些数据库可以被理论家用作基准，以指导计算方法的发展，提高计算后过渡金属表面化学反应能量的准确性。 虽然密度泛函理论（DFT）在催化研究中已经非常成功，但先前的结果证明，DFT吸附中间体能量的平均绝对误差超过20 kJ/mol。正在开发的实验数据库极大地促进了理论界正在进行的努力，以提高这种快速计算方法的能量准确性，同时也澄清了过渡金属催化中结构-反应性相关性的能量基础。这些改进对于催化研究具有变革性，使反应速率和机制的计算预测具有更高的可靠性，并且在预测可持续生活所必需的更好的催化剂和电催化剂材料方面具有更高的成功率。 这项研究还为众多年轻的科学和工程学生和博士后研究人员提供了强大的跨学科，研究综合教育，他们获得了最先进的测量仪器及其设计的实践经验。 除了指导这些年轻人，坎贝尔博士是参与广泛的推广到更广泛的社区，通过他频繁的公开讲座，许多编辑和咨询委员会成员，并服务于大学和外部科学教育的举措。

Catalysts are chemicals that provide more efficient and selective pathways for desirable chemical reactions. Transition metal catalysts are particularly useful in the production of bulk chemicals and fuels, and for cleaner fuel combustion and pollution cleanup. For these solid catalysts, metals at the catalyst surface bind the reacting chemicals with just the right strength (or "bond energy") to enable their chemical conversion to the desired products. Too tightly bound, and the product will not desorb but will remain attached to the catalyst surface. Too weakly bound and the reactant will not adsorb, and cannot react catalytically with it. Improving the energetics of such catalysts is essential for producing and using chemicals and fuels with higher energy efficiency and less pollution, as needed for sustainable living into the future. The key to improving the catalysts is to find materials whose surfaces bind the reacting chemicals with the optimum bond energies. In principle, this can be achieved by solving the equations of quantum mechanics (a branch of physics) with computers. Unfortunately, the math is very difficult, so mathematical approximations must be made for even the fastest computers to solve the equations in reasonable times. Experimental measurements of some of the bond energies are needed to compare to the computer results, to assess whether these approximations lead to incorrect bond energies. In this project, Dr. Charles T. Campbell is measuring bond energies for selected chemicals bound to transition metal surfaces, carefully chosen to enable development of new quantum mechanical methods for more accurately predicting such energies, and to improve the basic understanding of the catalyst's action. Improving the energy accuracy of such fast computations is transformative in the field of heterogeneous catalysis, enabling greater reliability in computer-based predictions of better catalyst materials. This research also provides strong interdisciplinary, research-integrated education for numerous young students, scientists and engineers, who get hands-on experience with state-of-the-art measurement instrumentation and its design. Dr. Campbell is involved in extensive outreach to the broader community, through his frequent public lectures, numerous editorships and advisory board memberships, and service to university and external science education initiatives.Late transition metal catalysts and electocatalysts are used in the production of bulk chemicals and fuels, for cleaner fuel combustion and for pollution cleanup. Improving such catalysts is essential for producing and using chemicals and fuels with higher energy efficiency and less pollution, as needed for sustainable living. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Charles T. Campbell of the University of Washington is measuring the energetics of selected elementary chemical reactions occurring on late transition metal surfaces, carefully chosen to enable development of new theoretical methods for more accurately predicting such energies. This, in turn, improves the basic understanding of catalytic mechanisms, and facilitates the design of better catalysts. Dr. Campbell's calorimetric measurements, which cannot be performed with the same precision elsewhere in the world, are broadening the database of reliable experimental energies of adsorbed catalytic intermediates that can be used by theoreticians as benchmarks to guide development of computational methods with improved accuracy for calculating the energetics of chemical reactions at late transition metal surfaces. While density functional theory (DFT) has been extremely successful in catalysis research, prior results proved that the mean absolute errors in the energies of adsorbed intermediates from DFT exceeds 20 kJ/mol. The experimental database being developed here greatly facilitates ongoing efforts by the theoretical community to improve the energy accuracy of such fast computational methods, while also clarifying the energetic basis for structure-reactivity correlations in transition metal catalysis. These improvements are transformative for catalysis research, enabling greater reliability in computational prediction of reaction rates and mechanisms, and higher success rates in predicting better catalyst and electrocatalyst materials that are essential for sustainable living. This research also provides strong interdisciplinary, research-integrated education for numerous young science and engineering students and postdoctoral researchers, who get hands-on experience with state-of-the-art measurement instrumentation and its design. In addition to mentoring these young people, Dr. Campbell is involved in extensive outreach to the broader community, through his frequent public lectures, numerous editorships and advisory board memberships, and service to university and external science education initiatives.