Mechanistic Insights into Covalent and Ionic Contributions to Molecular Adsorption and Reaction on Transition Metals

催化是一种化学物质为反应物（原料）化学品提供新的更容易的途径以生产更理想的产品的过程。催化化学品可以大大提高反应速率，使反应在更温和和更可控的条件下进行，并提高对所需产物的选择性（副产物更少）。目前，开发用于特定的理想反应的良好催化剂是具有挑战性的，并且需要对反应物和催化剂如何相互作用有很好的了解。在这个项目中，彭振孟博士正在研究一氧化碳（CO）氧化催化中过渡金属的反应器-催化剂相互作用的关键因素。Peng博士的方法是改进吸附模型，以便从易于执行的测量中准确计算这些相互作用。 在这项研究中获得的知识有助于显着加快寻找新的催化剂。催化在化学、石油化工和能源工业中起着至关重要的作用，催化材料被广泛用于化学转化和能源生产，因此其研究具有广泛的社会影响。 彭博士还积极参与一些外展活动，旨在培养高中生早期的科学兴趣，并影响他们在科学，技术，工程和数学（STEM）领域的职业发展。 他参与了K-12教师的纳米催化学习模块的开发，本科生和研究生的指导，社区学习网络课程的开发，以及与工程女性（WIE）和增加工程学术多样性（IDEA）计划的多样性外展工作在阿克伦大学。他还指导本科生和研究生，为他们未来在需要化学和工程知识的领域的职业生涯做好准备。在化学部化学催化项目的资助下，阿克伦大学的彭振梦博士正在开发一种改进的d带吸附能理论（Ead）模型，该模型使用易于测量的催化剂参数。 他正在使用一氧化碳氧化的多方法机理研究来测试这种改进。 为此，彭博士正在合成具有受控d带中心和功函数参数的模型催化剂，并研究它们与CO和O2吸附的相关性。 该研究采用Ead的反应物种，以获得信息的反应机理和其他重要的催化性能，这是具有挑战性的实验测量。通过建立精确的Ead-催化剂参数关系，彭博士可以表征吸附质和活性中间体与金属基体的结合，了解这些有助于理解催化机理，识别活性中间体，指导催化剂研究。 在假设d带理论中隐含包含共价和离子贡献可以显着提高理论的准确性的驱动下，Peng博士将金属d带中心和功函数分别与包含共价和离子部分的Ead相关联。 在这项研究中获得的知识有助于显着加快寻找新的催化剂。催化在化学、石油化工和能源工业中起着至关重要的作用，催化材料被广泛用于化学转化和能源生产，因此其研究具有广泛的社会影响。 彭博士积极参与了一系列外展活动，以支持该项目的更广泛影响，教育学生并提高公众对化学知识和技术的兴趣。K-12学生和代表性不足的少数民族学生是外联活动的特别目标。

Catalysis is a process in which one chemical substance provides a new and easier pathway for reactant (feedstock) chemicals to produce more desirable products. Catalytic chemicals can greatly enhance the reaction rates, which allows the reactions to proceed under milder and more controllable conditions, and improves the selectivity to the desired product (fewer by-products). Currently, developing a good catalyst for a specific, desirable reaction is challenging and requires good knowledge of how the reactants and catalyst interact. In this project, Dr. Zhenmeng Peng is researching the key factors that determine reactant-catalyst interactions for transition metals in carbon monoxide (CO) oxidation catalysis. Dr. Peng's approach is to improve upon an adsorption model for accurate calculation of these interactions from easy to perform measurements. Knowledge gained in this research helps to significantly accelerate the search for new catalysts. Catalysis plays an essential role in chemical, petrochemical and energy industries, with catalytic materials being widely used for chemical conversions and energy generation, and thus the research has broad societal impact. Dr. Peng is also actively engaged in a number of outreach activities, aimed at creating early scientific interest in high school students and influencing their career development in science, technology, engineering and mathematics (STEM) fields. He is involved in the development of a nanocatalysis learning module for K-12 teachers, mentoring of undergraduate and graduate students, development of a community learning network course, and diversity outreach efforts with Women in Engineering (WIE) and Increasing Diversity in Engineering Academics (IDEA) programs at the University of Akron. THe also mentors undergraduate and graduate students, preparing them for future careers in areas that require chemistry and engineering knowledge.With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Zhenmeng Peng at the University of Akron is developing an improved model of d-band theory of adsorption energy (Ead) using readily-measured catalyst parameters. He is using a multi-approach mechanistic study of carbon monoxide oxidation to test this improvement. To this aim, Dr. Peng is synthesizing model catalysts with a controlled d-band center and work function parameters and examining their correlations with CO and O2 adsorption. The research employs Ead of the reacting species to obtain information on the reaction mechanism and other important catalytic properties which are challenging to measure experimentally. Establishing an exact Ead-catalyst parameter relationship allows Dr. Peng to characterize adsorbate and reactive intermediate bonding to the metal substrate, the knowledge of which helps to understand the catalytic mechanism, identify reactive intermediates, and guide catalyst research. Driven by the hypothesis that implicit inclusion of both covalent and ionic contributions to d-band theory can significantly improve the accuracy of the theory, Dr. Peng relates the metal d-band center and work function to Ead for inclusion of the covalent and ionic fractions, respectively. Knowledge gained in this research helps to significantly accelerate the search for new catalysts. Catalysis plays an essential role in chemical, petrochemical and energy industries, with catalytic materials being widely used for chemicals conversion and energy generation, and thus the research has broad societal impact. Dr. Peng is actively engaged in a number of outreach activities, in support of the broader impacts of the project, to educate students and improve the public interest in chemistry knowledge and technology. K-12 students and underrepresented minority students are particularly targeted in the outreach activities.