CAREER: Spectrokinetic Studies for Understanding Metal-Support Interactions in Catalytic Oxidation of Ethanol

职业：用于了解乙醇催化氧化中金属-载体相互作用的光谱动力学研究

• 批准号: 1847655
• 负责人: Juan Bravo Suarez
• 金额: $ 50万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1847655&HistoricalAwards=false
• 关键词: CAREER; Spectrokinetic; Studies; Understanding; Metal

Ethanol is a major commodity chemical produced from biorenewable sources that is primarily used in transportation fuel. The project will focus on improved catalysts for expanding the ethanol market by converting the ethanol to value-added derivatives such as acetic acid. Specifically, the project will study the interactions between gold nanoparticles and metal oxide catalyst supports to gain fundamental understanding that will be used to design more active and selective catalysts for acetic acid production. The fundamental knowledge gained in this project will contribute to the long-term sustainability of U.S. bioethanol plants. Mechanistic insights will also provide better general understanding of metal-support interactions involving noble metals in applications such as automotive exhaust oxidation catalysis. The research is integrated with an educational plan that provides training and leadership opportunities to a diverse group of undergraduate and graduate students through research and community engagement.The project addresses the effects of charge transfer processes in heterogeneous catalysis. The limited number of experimental tools to assess in situ charge transfer rates and their kinetic relevance for surface catalyzed reactions has been a major obstacle for advancing the understanding of metal-support interactions. Three enabling spectroscopic techniques have been developed to facilitate 1) in situ evaluation of adsorbed oxygen on gold catalysts (Gold-Surface Plasmon Resonance-UV-visible spectroscopy, i.e. Au-SPR-UV-vis), 2) identify surface reaction intermediates (Modulation Excitation-Phase Sensitive Detection-Diffuse Reflectance Infrared Fourier Transform Spectroscopy, i.e. ME-PSD-DRIFTS), and charge transfer between metal and support (Modulation Excitation-Phase Sensitive Detection-UV-visible spectroscopy, i.e. ME-PSD-UV-vis). This project will systematically examine electronic and structural metal-support effects by studying a variety of catalysts while isolating gold particle size, support nature, and catalyst synthesis method. It is hypothesized that supports with n-type semiconducting properties facilitate charge transfer from and to the gold nanoparticle periphery, thereby promoting active species that oxidize ethanol to acetic acid. Overall, the combination of Au-SPR-UV-vis, ME-PSD-FTIR, ME-PSD-UV-vis, spectrokinetics, and reaction kinetics will provide a comprehensive mechanistic view of gas phase ethanol oxidation to describe the observed activity and selectivity trends. The new knowledge and techniques will assist in the design of next-generation gold oxidation catalysts. They will also be transferable to other oxidation reactions, thus expanding their applicability to a wide range of surface catalyzed reactions. The research and educational programs will produce a trained cadre of diverse students to enter the workforce in STEM disciplines. A new outreach after-school science initiative, EMPower (Energy, Matter, & Power) club, will also provide undergraduate students with leadership opportunities while serving as role models and mentors for elementary school children from underrepresented groups and low-income backgrounds. The initiative will serve as a catalyst to spark children's curiosity through hands-on activities to let them appreciate science with fun activities and inspire them to pursue education in STEM fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

乙醇是从生物可再生来源生产的主要商品化学品，主要用于运输燃料。 该项目将侧重于改进催化剂，通过将乙醇转化为乙酸等增值衍生物来扩大乙醇市场。 具体而言，该项目将研究金纳米颗粒和金属氧化物催化剂载体之间的相互作用，以获得基本的理解，用于设计更活性和选择性的乙酸生产催化剂。 在这个项目中获得的基本知识将有助于美国生物乙醇工厂的长期可持续性。机制的见解也将提供更好的一般理解的金属载体相互作用，涉及贵金属的应用，如汽车尾气氧化催化。该研究与教育计划相结合，通过研究和社区参与为不同的本科生和研究生群体提供培训和领导机会。该项目解决了多相催化中电荷转移过程的影响。有限数量的实验工具，以评估在原位电荷转移速率和它们的动力学相关的表面催化反应一直是一个主要的障碍，为推进理解的金属载体相互作用。三个使光谱技术已经发展，以促进1）在原位评价吸附的氧在金催化剂上（金-表面等离子体共振-UV-可见光谱，即Au-SPR-UV-vis），2）鉴定表面反应中间体（调制激发-相敏检测-漫反射红外傅里叶变换光谱，即ME-PSD-DRIFTS），以及金属和载体之间的电荷转移（调制激发-相敏检测-UV-可见光谱，即ME-PSD-UV-vis）。该项目将通过研究各种催化剂，同时分离金颗粒大小，载体性质和催化剂合成方法，系统地研究电子和结构金属载体效应。据推测，支持与n型半导体性能促进电荷转移和金纳米粒子的外围，从而促进活性物质，氧化乙醇到乙酸。总之，Au-SPR-UV-vis，ME-PSD-FTIR，ME-PSD-UV-vis，光谱动力学和反应动力学的组合将提供气相乙醇氧化的综合机理视图，以描述观察到的活性和选择性趋势。新的知识和技术将有助于下一代金氧化催化剂的设计。它们也可以转移到其他氧化反应中，从而将它们的适用性扩展到广泛的表面催化反应。研究和教育计划将培养出一支训练有素的多元化学生队伍，进入STEM学科的劳动力队伍。一个新的外展课后科学倡议，赋权（能源，物质，权力）俱乐部，也将提供本科生的领导机会，同时作为榜样和导师的小学儿童从代表性不足的群体和低收入背景。该计划将作为一种催化剂，通过动手活动激发孩子们的好奇心，让他们通过有趣的活动欣赏科学，并激励他们在STEM领域追求教育。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Degradation of diclofenac aqueous solutions in a 3D electrolytic reactor using carbon-based materials as pseudo third electrodes in fluidized bed, anodic and cathodic configurations

• DOI: 10.1016/j.jece.2022.108075
• 发表时间: 2022-06
• 期刊: Journal of Environmental Chemical Engineering
• 影响因子: 7.7
• 作者: Jawer Acuña-Bedoya;Christian E. Alvarez-Pugliese;S. F. Castilla-Acevedo;Juan J. Bravo-Suárez;N. Marriaga-Cabrales

In situ UV–vis plasmon resonance spectroscopic assessment of oxygen and hydrogen adsorption location on supported gold catalysts

原位紫外可见等离子体共振光谱评估负载金催化剂上氧和氢的吸附位置

• DOI: 10.1016/j.mcat.2021.111572
• 发表时间: 2021
• 期刊: Molecular Catalysis
• 影响因子: 4.6
• 作者: Srinivasan, Priya D.;Zhu, Hongda;Bravo-Suárez, Juan J.
• 通讯作者: Bravo-Suárez, Juan J.

In situ Raman spectroscopy study of silver particle size effects on unpromoted Ag/α-Al2O3 during ethylene epoxidation with molecular oxygen

原位拉曼光谱研究乙烯分子氧环氧化过程中银粒径对未促进的 Ag/α-Al2O3 的影响

• DOI: 10.1016/j.jcat.2023.01.016
• 发表时间: 2023
• 期刊: Journal of Catalysis
• 影响因子: 7.3
• 作者: Alzahrani, Hashim A.;Bravo-Suárez, Juan J.
• 通讯作者: Bravo-Suárez, Juan J.