SusChEM: CO2 Photo-Electrochemistry on Metal Oxides Surfaces Studied by Vibrational Sum Frequency Generation Spectroscopy and Density Functional Theory

SusChEM：通过振动和频发生光谱和密度泛函理论研究金属氧化物表面上的 CO2 光电化学

• 批准号: 1665280
• 负责人: Lawrence Baker
• 金额: $ 44.95万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1665280&HistoricalAwards=false
• 关键词: SusChEM; CO2; Photo; Electrochemistry; Metal

Catalysts are chemical substances that provide lower-energy reaction pathways to increase the speed of a chemical reaction. Catalysts can be recycled many times during a chemical reaction. Some catalysts, called photo-electrocatalysts, are able to use light as an energy source to produce the reaction of interest. In this project, funded by the Chemical Catalysis Program of the Chemistry Division, Professors L. Robert Baker and Aravind Asthagiri are using a combination of an experimental technique called sum frequency generation (SFG) vibrational spectroscopy and computational modeling called density functional theory (DFT) to investigate carbon dioxide (CO2) reduction by a series of copper and copper/iron containing photo-electrocatalysts. SFG vibrational spectroscopy is able to show how molecules important in CO2 reduction interact with the catalyst surfaces during the reaction. DFT calculations are used to help explain the SFG data generated during the reaction. The combination of the two techniques leads to a complete picture of the surface reaction mechanism, allowing for better design of the catalyst and the photo-electrocatalysis process. The ability to photo-electrochemically reduce CO2 using sunlight has the potential to enable us to recycle carbon and stabilize the environmental impacts of CO2 emissions from automobiles and other sources. This research helps to address the challenge of making fuels in an environmentally friendly and economically viable way. These research activities are integrated with an outreach plan to improve student recruitment and retention in science, technology, engineering and mathematics (STEM) fields. Through the TEK8 program at the Ohio State University, undergraduate students and K-12 teachers gain hands-on experience in the investigators' research groups. The students then translate this experience to middle school students through age-appropriate learning modules designed to inspire K-12 students to pursue future STEM education.The challenge of understanding CO2 surface chemistry on a photo-electrocatalyst requires a combined knowledge of metal oxide surface chemistry as well as the semiconductor photo-physics that determine the localized atomic sites of photo-excited electrons responsible for driving the reductive chemistry. In this project funded by the Chemical Catalysis Program of the Chemistry Division, Professors L. Robert Baker and Aravind Asthagiri are using sum frequency generation (SFG) spectroscopy and complementary density functional theory (DFT) computational modeling to investigate CO2 activation and subsequent reduction on a series of CuO/CuFeO2 surfaces as a function of relative phase composition. CuO/CuFeO2 catalysts with varying amounts of CuO and CuFeO2 show tunable selectivity between acetate and formate production. The ability to probe the molecular intermediates associated with these reaction pathways, coupled with the ability to tune these relative rates, is providing a valuable case study for a thorough mechanistic investigation of the surface properties that mediate reaction kinetics leading to tunable selectivity for CO2 reduction. Complementary measurements using femtosecond soft x-ray spectroscopy show electron thermalization kinetics and site-specific charge localization with element specificity. Through information from the soft x-ray spectroscopy and DFT-derived band structure, the team obtains the reduction potential of site-localized photo-excited electrons in the oxide surface and compares these potentials to the calculated change in free energy of formation of elementary steps on these respective atomic sites. This combination of approaches bridges the fields of semiconductor photo-physics with surface chemistry and catalysis in order to provide a fundamental framework for understanding the selectivity of CO2 photo-electrochemistry on metal oxides surfaces. This research helps to address the challenge of environmentally friendly and economically stable fuel production and chemical synthesis from CO2 using earth-abundant metal oxide catalysts. These research activities are integrated with an outreach plan to improve student recruitment and retention in STEM fields. Through the TEK8 program at the Ohio State University, undergraduate students and K-12 teachers gain hands-on experience in the investigators' research groups. They then translate this experience to middle school students through age-appropriate learning modules designed to inspire K-12 students to pursue future STEM education.

催化剂是化学物质，可提供较低的能源反应途径，以提高化学反应的速度。 在化学反应期间，催化剂可以多次回收。 一些称为照片 - 电催化剂的催化剂能够使用光作为产生感兴趣反应的能源。 In this project, funded by the Chemical Catalysis Program of the Chemistry Division, Professors L. Robert Baker and Aravind Asthagiri are using a combination of an experimental technique called sum frequency generation (SFG) vibrational spectroscopy and computational modeling called density functional theory (DFT) to investigate carbon dioxide (CO2) reduction by a series of copper and copper/iron containing photo-electrocatalysts. SFG振动光谱能够显示在反应过程中与催化剂表面相互作用中重要的分子。 DFT计算用于解释反应过程中产生的SFG数据。 两种技术的组合导致了表面反应机理的完整图片，从而可以更好地设计催化剂和光电催化过程。 使用阳光照相将电化学降低二氧化碳的能力有可能使我们能够回收碳并稳定汽车和其他来源的二氧化碳排放量的环境影响。 这项研究有助于应对以环保且经济上可行的方式制作燃料的挑战。 这些研究活动与推广计划融合，旨在改善学生在科学，技术，工程和数学（STEM）领域的招聘和保留。 通过俄亥俄州立大学的TEK8计划，本科生和K-12教师在调查人员的研究小组中获得了动手经验。 The students then translate this experience to middle school students through age-appropriate learning modules designed to inspire K-12 students to pursue future STEM education.The challenge of understanding CO2 surface chemistry on a photo-electrocatalyst requires a combined knowledge of metal oxide surface chemistry as well as the semiconductor photo-physics that determine the localized atomic sites of photo-excited electrons responsible for driving the reductive chemistry. 在化学部化学催化计划资助的项目中，罗伯特·贝克（L. Robert Baker）和阿拉维德·阿塔西里（Aravind Atthagiri）教授使用总和频率产生（SFG）光谱和互补密度功能理论（DFT）计算模型来研究CO2激活和随后的Cuo/Cufeo2 cufeo2 Surface Surface As a a in a -Compositions的cuo/cufeo2降低。 CUO/CUFEO2催化剂具有不同量的CUO和CUFEO2在乙酸盐和甲酸盐生产之间显示可调的选择性。 探测与这些反应途径相关的分子中间体的能力，再加上调整这些相对速率的能力，为对表面特性进行了彻底的机械研究提供了一个有价值的案例研究，以介导反应动力学，从而导致可调性选择性，以减少CO2。 使用飞秒软X射线光谱的互补测量结果显示了电子热动力学和特定于元素特异性的特定位置电荷定位。 通过来自软X射线光谱和DFT衍生带结构的信息，该团队在氧化物表面中获得了位点 - 定位的光启用电子的降低潜力，并将这些潜力与这些各自的原子位点的基本步骤形成的自由能的计算变化进行了比较。 这种方法的组合桥接了半导体光物理学与表面化学和催化的场，以提供一个基本框架，以了解金属氧化物表面上CO2光电化学的选择性。 这项研究有助于解决环保且经济上稳定的燃料生产和使用氧化金属氧化物催化剂从CO2产生的化学合成的挑战。 这些研究活动与推广计划集成在一起，以改善学生在STEM领域的招聘和保留。 通过俄亥俄州立大学的TEK8计划，本科生和K-12教师在调查人员的研究小组中获得了动手经验。 然后，他们通过适合年龄的学习模块将这种经验转化为中学生，旨在激发K-12学生进行未来的STEM教育。

项目成果

The role of phase impurities and lattice defects on the electron dynamics and photochemistry of CuFeO2 solar photocathodes

• DOI: 10.1007/s12274-019-2493-6
• 发表时间: 2019-08
• 期刊: Nano Research
• 影响因子: 9.9
• 作者: E. Fugate;S. Biswas;Mathew C. Clement;Minkyu Kim;Dongjoon Kim;A. Asthagiri;L. R. Baker

Plasmon-Resonant Vibrational Sum Frequency Generation of Electrochemical Interfaces: Direct Observation of Carbon Dioxide Electroreduction on Gold

电化学界面的等离子共振振动和频率生成：金上二氧化碳电还原的直接观察

• DOI: 10.1021/acs.jpca.0c04268
• 发表时间: 2020
• 期刊: The Journal of Physical Chemistry A
• 作者: Wallentine, Spencer;Bandaranayake, Savini;Biswas, Somnath;Baker, L. Robert
• 通讯作者: Baker, L. Robert