SusChEM: Mechanistic Studies of Photocatalytic Water-Splitting and CO2Reduction: The control of surface chemical reactivity and its effect on product distribution

SusChEM：光催化分解水和CO2还原的机理研究：表面化学反应性的控制及其对产物分布的影响开发廉价的催化材料，有效地利用太阳能将简单，容易获得的物质转化为可持续生产的燃料和化学品是21世纪世纪的重大挑战之一。 这种光催化过程被称为“人工光合作用”，并因其承诺从二氧化碳（CO2）和水（H2O）中提供廉价，清洁的能源和化学品而受到追捧。 目前，科学家们还不完全了解如何控制光催化反应，从大量潜在产品中生产出最理想的化学品。 在这个项目中，Laursen博士正在研究如何控制人工光合作用的表面化学反应。 如果我们要按照我们社会的需要，以对环境负责的方式有选择地生产燃料或基本化学品，那么高度的控制至关重要。 Laursen博士积极参与外联活动，以他的研究为基础，促进学生参与科学，技术，工程和数学（STEM）学科。 这些活动包括在Laursen博士的实验室进行暑期研究实习，旨在改善有前途的高中毕业生和女学生的教育，并鼓励他们对STEM职业的兴趣。 在化学部化学催化项目的资助下，田纳西大学诺克斯维尔分校的Siris Laursen博士正在对Bi 2S 3、GaP和CdS半导体光催化剂的表面性质如何决定其在将CO2和H2O还原为氢气、甲烷和简单含氧烃中的催化活性和产物选择性进行基本了解。 在决定催化剂功效的机制中重要的表面结合的中间体随后用原位漫反射红外傅里叶变换光谱（DRIFTS）将各种中间体物种的热化学稳定性与反应速率和产物选择性相关联。 也在研究中的是如何控制表面结合氢的化学性质，以产生优先于分子氢或一氧化碳的还原有机分子。 密度泛函理论（DFT）计算与实验工作并行进行，并用于支持结构-活性和组成-活性性质测定。 劳尔森积极参与STEM外展计划，重点是女学生招募到STEM领域和高中学生研究实习，以支持该项目的更广泛影响。

SusChEM: Mechanistic Studies of Photocatalytic Water-Splitting and CO2 Reduction: The control of surface chemical reactivity and its effect on product distributionDeveloping inexpensive catalytic materials that efficiently use solar energy to transform simple, readily-available substances into sustainably-produced fuels and chemicals is one of the grand challenges of the 21st century. This photocatalytic process is called "Artificial Photosynthesis" and is pursued for its promise of supplying cheap, clean energy and chemicals from carbon dioxide (CO2) and water (H2O). Currently, scientists do not completely understand how photocatalytic reactions can be controlled to produce the most desirable chemicals out of a large number of potential products. In this project, Dr. Laursen is developing an understanding of exactly how to control the surface chemical reactivity of Artificial Photosynthesis. A high level of control is critical if we are to produce the fuel or building-block chemicals selectively in an environmentally responsible fashion, as needed by our society. Dr. Laursen is actively engaged in outreach activities that build upon his research to promote engagement of students in science, technology, engineering and mathematics (STEM) disciplines. These activities, which include summer research internships in Dr. Laursen's laboratory, are directed at improving the education of promising high school seniors and women students and encouraging their interest in STEM careers. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Siris Laursen of the University of Tennessee - Knoxville is developing a fundamental understanding of how the surface properties of Bi2S3, GaP, and CdS semiconductor photocatalysts dictate their catalytic activity and product selectivity in the reduction of CO2 and H2O to hydrogen, methane and simple oxygenated hydrocarbons. The surface-bound intermediates important in the mechanisms that determine catalyst efficacy are followed with in situ Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTS) to correlate the thermochemical stability of the various intermediate species with reaction rate and product selectivity. Also under investigation is how the chemical nature of surface bound hydrogen can be controlled to produce reduced organic molecules preferentially over molecular hydrogen or carbon monoxide. Density functional theory (DFT) calculations are carried out in parallel to the experimental work, and are used in support of structure-activity and composition-activity property determination. Dr. Laursen is actively engaged in STEM outreach programs focused on female student recruitment into the STEM fields and in high school student research internships, in support of the broader impacts of the project.