Mechanistic Insights into the Structure Sensitivity of Hydrocarbon Conversions Catalyzed by Metal Surfaces

在这个由化学系化学催化项目资助的项目中，滨江加州大学的弗朗西斯科扎埃拉教授正在研究碳氢化合物在金属表面从一种化合物转化为另一种化合物的分子过程，也称为催化。 烃转化反应的催化是许多工业过程的核心，包括炼油、精细化学合成和食品加工。 催化中的主要挑战之一是实现一种产物对所有其他潜在产物的高选择性，这将避免浪费原料并将污染副产物的产生最小化。 已经表明，在金属表面上的某些催化中，选择性可以通过表面的原子级结构的变化来控制，并且这种控制为设计非常理想的工业过程提供了新的途径。 在这个项目中，Zaera教授专注于测试具体的例子，其中可以通过使用具有特定形状的金属纳米颗粒来控制碳氢化合物转化。 正在使用三种互补的实验方法：高通量分子束，以获得在受控环境下具有不同结构的模型金属样品的精确动力学参数，通过红外（IR）光谱法原位表征相应吸附物质的操作安排，以及一个反应器，用于对由具有特定形状的金属纳米颗粒分散在高分子材料上制成的更现实的催化剂进行动力学和IR表征。表面积支持。 该项目涉及研究生培训，重点是利用若干国际外联活动，从科学研究领域代表性不足的群体中招收学生。 该项目的更广泛影响还包括可能开发用于能源和其他用途的清洁催化工艺。

In this project funded by the Chemical Catalysis program of the Chemistry Division, Professor Francisco Zaera of the University of California, Riverside is investigating the molecular processes by which hydrocarbons are converted from one compound to another on the surface of a metal, also termed catalysis. The catalysis of hydrocarbon conversion reactions is central to many industrial processes, including oil refining, fine chemical synthesis, and food processing. One of the major challenges in catalysis is to achieve high selectivity for one product over all other potential products, which would avoid wasting feedstocks and would minimize the production of polluting byproducts. It has been shown that, in some catalysis on metal surfaces, selectivity may be controlled through variations in the atomic level structure of the surface, and this control offers new avenues for the design of highly desirable industrial processes. In this project, Professor Zaera focuses on testing specific examples where hydrocarbon conversion may be controlled by using metal nanoparticles with specific shapes. Three complementary experimental approaches are being used: a high-flux molecular beam to obtain accurate kinetic parameters for model metal samples with different structures under controlled environments, an operando arrangement for the in-situ characterization of corresponding adsorbed species by infrared (IR) spectroscopy, and a reactor for the kinetic and IR characterization of more realistic catalysts made out of metal nanoparticles with specific shapes dispersed on high-surface-area supports. This project involves the training of graduate students, with an emphasis in recruiting students from groups underrepresented in science research fields by taking advantage of the several international outreach activities. The broader impacts of this project also include the potential development of cleaner catalytic processes for energy and other applications.