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理解复杂的、通常有缺陷的材料表面的性质和化学转化。表面科学彻底改变了催化在工业中的应用，包括利用金属单晶的基本发现，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理解现在可以彻底改变催化剂的使用，指导硫化物催化剂在诸如生物质价值化，从环境中去除挥发性有机碳和光催化能源生产等行业中的使用。本文提出的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，以及它们与芳香和含氧有机物质的相互作用。我们将对化学反应、机理和中间体的基本理解与在此基础上制备的纳米结构材料的合成和使用相结合的独特方法，提高了催化性能，并推广了共同因素（反应位点、中间体、分子几何等），这将指导未来的催化剂设计。硫化物的表面性质，如界面的偏析、表面终止和硫或氢在不同环境中的不稳定性，决定了分子与表面的相互作用。总的来说，我们将有助于对催化剂反应性的总体理解，并具有广泛的预测能力，因为它们在催化和光催化反应中的性质。该提案旨在在5年拨款期间每年培训5名hqp。我们将首先使用CdS和ZnS单晶表面和纳米颗粒：-制备和理解明确定义的硫化物表面-识别和表征在明确定义的硫化物表面上的有机分子的吸附种类-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-提供有关反应中间体和机制的见解-合成和测试具有所需表面的可控纳米催化剂。我们希望开发可行的催化剂，并确定催化和光催化去除挥发性有机碳的反应条件。这对我们的环境至关重要，导致设备提供清洁的家庭气氛或去除大气污染物。同样，我们的目标是获得一种活性材料，用于生物质衍生分子的氢脱氧，从而在生物质增值方面产生高经济影响。

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.