CAREER: Supports as steric and electronic modifiers of catalysis at single atom metal active sites

通过分离的金属原子促进催化反应负载金属催化剂，特别是那些使用昂贵的贵金属如铑（Rh）的催化剂，通常在贵金属分散成极小的颗粒时最有效地利用-并且在极限情况下作为分离的金属原子。本研究在基础水平上考察了支撑氧化物材料和活性贵金属之间的相互作用如何被设计来控制分离Rh原子的稳定性和活性。这项工作的见解将用于设计丙烯氢甲酰化的高选择性催化剂-目前在均相液相催化条件下操作的重要工业反应。一种异质气相模拟物——正如本文所寻求的——将提供成本更低、更环保的替代方案。此外，这项研究将为加州大学河滨分校广泛多样化的学生群体提供发展成功技术职业所需的分析和沟通技能的机会。该项目的重点是控制选择性，反应性和稳定性的分离金属原子催化剂通过改变氧化物载体和有机硅烷基团功能化载体的方式，创建复制那些单金属原子均相催化剂的电子和立体结构。该研究的核心是一系列涉及合成、原位催化剂转化和分析方法的技术，这些技术将用于创建、确认和表征分离的原子位点，并控制它们的活性和稳定性。基础实验将使用探针分子光谱，探针反应动力学，原位光谱和显微镜，以及密度泛函理论计算。虽然目前的重点将放在丙烯氢甲酰化上，但相关的基本理解将通过设计比均相过程更节能和更环保的多相催化过程使社会受益。该项目的高度多学科性质将为这所西班牙裔服务机构的学生提供丰富的机会，以发展基于仔细推理和结构化科学论据的技术信息表达技能。

1554112 Christopher, PhillipPromoting Catalytic Reactions Via Isolated Metal AtomsSupported metal catalysts, especially those utilizing expensive noble metals such as rhodium (Rh), are often most effectively utilized when the noble metal is dispersed as extremely small particles - and in the limit as isolated metal atoms. This study examines at a fundamental level how interactions between the supporting oxide material and the active noble metal can be engineered to control the stability and activity of isolated Rh atoms. Insights from the work will be used to design catalysts with high selectivity in propylene hydroformylation - an important industrial reaction currently operated under homogeneous liquid-phase catalytic conditions. A heterogeneous, gas-phase analog - as sought here - would offer a lower cost, environmentally friendly alternative. Additionally, the research will provide opportunities for a broadly diverse student body at UC Riverside to develop both the analytical and communication skills needed for successful technical careers.The project focuses on controlling the selectivity, reactivity, and stability of isolated metal atom catalysts by varying the oxide support and by functionalizing the support with organosilane moieties in ways that create electronic and steric structures that replicate those of single-metal-atom homogeneous catalysts. Central to the study are a host of techniques involving synthesis, in-situ catalyst transformations, and analytical methods that will be utilized to create, confirm, and characterize the isolated atom sites and control their activity and stability. Fundamental experiments will be carried out using probe molecule spectroscopy, probe reaction kinetics, in-situ spectroscopy and microscopy, and density functional theory calculations. While the immediate focus will be on propylene hydroformylation, the associated fundamental understanding will benefit society through the design of heterogeneous catalytic processes that are more energy and environmentally friendly than homogeneous processes. The highly multidisciplinary nature of the project will provide plentiful opportunities for students at this Hispanic serving institution to develop skills in presenting technical information based on carefully reasoned and structured scientific arguments.