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

催化剂是为理想的化学反应提供更有效和更有选择性的途径的化学物质。过渡金属催化剂在生产散装化学品和燃料、清洁燃料燃烧和清除污染方面特别有用。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”)将反应化学品结合在一起，使它们能够化学转化为所需的产品。绑得太紧，产品不会解吸，而是会附着在催化剂表面。太弱的结合，反应物将不会吸附，也不能与其发生催化反应。改善这类催化剂的能量学对于生产和使用能源效率更高、污染更少的化学品和燃料至关重要，因为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与反应化学物质结合在一起并具有最佳键能的材料。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)的方程来实现。不幸的是，数学计算非常困难，所以即使是速度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。需要对一些键能进行实验测量，以便与计算机结果进行比较，以评估这些近似是否会导致不正确的键能。在这个项目中，Charles T.Campbell博士正在测量与过渡金属表面结合的选定化学物质的键能，经过精心挑选，以便开发新的量子力学方法来更准确地预测此类能量，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精确度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的预测更加可靠。这项研究还为众多年轻学生、科学家和工程师提供了强有力的跨学科、研究集成教育，他们获得了最先进的测量仪器及其设计的实践经验。坎贝尔博士通过频繁的公开演讲、多次担任编辑和顾问委员会成员，以及为大学和外部科学教育项目服务，参与了对更广泛社区的广泛宣传。最新的过渡金属催化剂和电催化剂被用于生产散装化学品和燃料、清洁燃料燃烧和污染清理。改进这种催化剂对于生产和使用能源效率更高、污染更少的化学品和燃料至关重要，因为这是可持续生活所需的。在化学系化学催化计划的资助下，华盛顿大学的Charles T.Campbell博士正在测量在后过渡金属表面上发生的选定基本化学反应的能量学，这些反应经过精心挑选，以便开发新的理论方法来更准确地预测这些能量。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，它拓宽了可靠的吸附催化中间体实验能量的数据库，理论家可以将其用作基准，指导计算方法的发展，提高计算过渡金属表面化学反应的能量的准确性。虽然密度泛函理论(DFT)在催化研究中非常成功，但以往的结果证明，DFT吸附中间体的能量的平均绝对误差超过20kJ/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精度，同时也澄清了过渡金属催化中结构-反应性关联的能量基础。这些改进对催化研究具有变革性，使反应速度和机理的计算预测更可靠，预测对可持续生存至关重要的更好的催化剂和电催化剂材料的成功率更高。这项研究还为众多年轻的理工科学生和博士后研究人员提供了强有力的跨学科、研究集成教育，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，坎贝尔博士还通过频繁的公开演讲、多次担任编辑和顾问委员会成员以及为大学和外部科学教育计划服务，参与了广泛的社区推广活动。

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.