Sulfide catalysts for biomass valorization and environmental remediation: Interactions of complex organic molecules on well-defined sulfide surfaces

对明确定义的硫化物表面以及它们如何与有机分子相互作用的研究一直缺乏。我们的目标是通过将表面科学技术与材料/催化工作相结合来填补这一空白，并开辟催化研究的新领域。我的研究计划的总体长期目标是在分子水平上了解复杂的、通常是有缺陷的材料表面的性质和化学转化。表面科学使催化在工业中的使用发生了革命性的变化，使用金属单晶的基础发现以及随后在超高真空中对氧化物、薄膜和纳米颗粒的研究。对硫化物表面分子-表面相互作用的基本了解现在可以彻底改变催化剂的使用，指导硫化物催化剂在生物质价态、从环境中去除挥发性有机碳和光催化生产能源等行业中的使用。表面科学和材料之间的相互作用将导致新的硫化物催化剂的制备和表征，以及它们与芳香族和含氧有机物种的相互作用。我们独特的方法将对化学反应、机理和中间体的基本了解与在此基础上制备的纳米结构材料的合成和使用结合在一起，从而提高了催化性能，并概括了将指导未来催化剂设计的共同因素(反应位置、中间体、分子几何结构等)。硫化物的表面性质，如界面处的偏析、表面终止和硫或氢在不同环境中的不稳定性，决定了分子-表面的相互作用。总体而言，我们将有助于全面了解催化剂的反应性，并对其催化和光催化反应的性质进行广泛的预测。这项建议的目的是在5年的拨款过程中，每年培训5名总部质检人员。我们将首先使用硫化镉和硫化锌单晶表面和纳米颗粒来：-制备和了解定义良好的硫化物表面-识别和表征有机分子在定义良好的硫化物表面上的吸附物种-识别和表征与加氢、氧化和加氢脱氧反应相关的反应物的共吸附行为-提供关于反应中间体和机理的见解-合成和测试具有所需表面的受控纳米催化剂这项工作的影响是多方面的。我们希望开发出可行的催化剂，并确定催化和光催化去除挥发性有机碳的反应条件。这对我们的环境是必不可少的，导致设备提供清洁的家庭环境或去除大气污染物。同样，我们的目标是实现一种活性材料，用于生物质衍生分子的加氢脱氧，从而在生物质的有价化中产生高度的经济影响。

The study of well-defined sulfide surfaces and how they interact with organic molecules has been lacking. We aim to fill this gap by combining surface science techniques with material/catalysis work and open a new area of investigation in catalysis. The general long-term objective of my research program is to understand, at the molecular level, the properties and chemical transformations of complex, usually defective material surfaces. Surface science revolutionized the use of catalysis in industry with fundamental discoveries using metal single crystals and subsequent work on oxides, films and nanoparticles in ultra high vacuum. Fundamental understanding of molecule-surface interactions on sulfide surfaces can now revolutionize catalyst usage, guiding sulfide catalyst use in industries such as biomass valorization, volatile organic carbon removal from the environment and photocatalysis for energy production. The interplay between surface science and materials proposed here will lead to the preparation and characterization of new sulfide catalysts and their interactions with aromatic and oxygenated organic species. Our unique approach of combining fundamental understanding of the chemical reactions, mechanisms and intermediates with the synthesis and use of nano-structured materials prepared on this basis leads to enhanced catalytic performance and the generalization of common factors (reaction sites, intermediates, molecular geometries, etc) that will guide future catalyst design. Surface properties of the sulfides such as segregation at the interphase, surface termination and sulfur or hydrogen lability in different environments determine the molecule-surface interactions. Overall, we will contribute to an overarching understanding of catalyst reactivity with extensive predictive power as to their properties for both catalytic and photocatalytic reactions. The proposal is designed for 5 HQPs per year to be trained over the course of the 5 year grant. We will initially use CdS and ZnS single crystal surfaces and nanoparticles to: -Prepare and understand well defined sulfide surfaces -Identify and characterize adsorption species of organic molecules on the well defined sulfide surfaces -Identify and characterize co-adsorption behavior for reactants relevant to hydrogenation, oxidation and hydrodeoxygenation reactions -Provide insight regarding reaction intermediates and mechanisms -Synthesize and test controlled nano-catalysts with the desired surfaces The impact of this work is manifold. We hope to develop viable catalysts and identify reaction conditions for catalytic and photocatalytic removal of volatile organic carbons. This is essential for our environment, leading to devices that provide a clean household atmosphere or to the removal of atmospheric pollutants. Similarly, we aim to achieve an active material for the hydrodeoxygenation of biomass derived molecules leading to a high economic impact in the valorization of biomass.