Collaborative Research: SusChEM: Manipulation of Reaction Selectivity in the electrochemical environment for biomass-to-chemicals conversions

从植物物质（生物质）中提取的燃料和化学品是可持续地满足对能源和商品产品需求的一种很有前途的手段。生物质是一种“碳中性”原料，因为它通过吸收大气中的二氧化碳而生长，同时只消耗太阳能。这个项目正在寻找新的和有效的途径，从目前难以加工的生物质成分中产生有用的化学物质。虽然目前大多数生物质转化都是使用催化剂和热能来进行的，但这项工作正在开发电力驱动的催化反应的独特方面，以便在低温和低压下合成有用的化学物质。这些过程所需的电力反过来可能来自风能和太阳能等可再生能源。目前正在采取的一种基本方法是，将探索催化反应性质的实验技术与计算机模拟相结合，以建立控制反应选择性因素的全面图景，并设计更有效的过程。本工作的见解在扩大绿色化学的范围方面具有更广泛的应用。这项研究还被用于促进科学教育，让本科生研究人员参加暑期实习，此外，PI还开发了一系列与理解控制电催化反应的物理过程有关的互动教育模块。该项目正在研究电化学控制生物质原料转化为所需化学目标的选择性。电化学转化在可持续处理方面具有优势，因为它们通常在低温下操作，并直接利用水性原料。使用选择性氧化的糠醛和5-羟甲基糠醛在Pt电极作为探针系统，这项工作的重点是确定不同的机制，通过控制电极电位和组成来操纵选择性。正在探索的机制包括相对于中性原子转移反应的电荷转移反应的差异，氧和有机物质表面覆盖的变化，以及具有特定反应活性或几何形状的促进剂的作用。目前正在整合三种互补的研究方法，以确定这些影响的特征。金属催化剂的电化学动力学测量与原位光谱相结合，以确定反应途径；采用表面科学实验对模型Pt（111）表面进行了详细的氧化基本步骤研究；最后，密度泛函理论计算用于研究相同的表面化学，包括电势效应和水-金属界面的模拟。这三个研究重点提供了互补的信息，丰富了对电化学环境的理解深度。本研究成果在拓展绿色化学和电化学合成路线方面具有广阔的应用前景。这项研究还被用于促进科学教育，让本科生研究人员参加暑期实习，此外，PI还开发了一系列与理解控制电催化反应的物理过程有关的互动教育模块。

Manipulation of reaction selectivity in the electrochemical environment for biomass-to-chemicals conversions Fuels and chemicals derived from plant matter (biomass) are a promising means to sustainably meet demands for energy and commodity products. Biomass is a "carbon neutral" feedstock because it grows by incorporating CO2 from the atmosphere while only consuming solar energy. This project is finding new and efficient outlets to generate useful chemicals from components of biomass that are currently difficult to process. While most biomass conversions are presently performed using catalysts and energy supplied by heat, this work is exploiting unique aspects of electricity-driven catalytic reactions in order to achieve synthesis of useful chemicals at low temperatures and pressures. The electricity required for these processes may, in turn, be derived from renewable sources such as wind and solar. A fundamental approach is being taken in which experimental techniques that probe the nature of the catalytic reactions are combined with computer simulations to build a comprehensive picture of the factors that govern reaction selectivity and to design more efficient processes. Insights from this work have broader application in extending the scope of green chemistry. This research is also being used to promote science education by involving undergraduate student researchers for summer internships, and the PI's are additionally developing a series of interactive educational modules related to understanding the physical processes governing electro-catalytic reactions. This project is investigating electrochemical control over selectivity in the conversion of biomass-derived feedstocks to desired chemical targets. Electrochemical conversions offer advantages in sustainable processing since they generally operate at low temperatures and utilize aqueous feedstocks directly. Using selective oxidation of furfural and 5-hydroxymethyl furfural over Pt electrodes as probe systems, this work focuses on determining the different mechanisms by which selectivity can be manipulated through control over electrode potential and composition. Mechanisms being explored include differentiation of charge-transfer reactions relative to neutral atom transfer reactions, variation in surface coverage of oxygen and organic species, and the role of promoters with specific reactivity or geometry. Three complementary research approaches are being integrated to characterize these effects. Measurement of electrochemical kinetics on metal catalysts is combined with in-situ spectroscopy to identify reaction pathways; surface science experiments are used on a model Pt(111) surface to study oxidation elementary steps in detail; and finally, density functional theory calculations are used to investigate the same surface chemistry, including simulation of electric potential effects and the water-metal interface. The three research thrusts provide complementary information and enrich the depth of understanding of the electrochemical environment. Insights from this work have broader application in extending the scope of green chemistry and electrochemical synthetic routes. This research is also being used to promote science education by involving undergraduate student researchers for summer internships, and the PI's are additionally developing a series of interactive educational modules related to understanding the physical processes governing electro-catalytic reactions.