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

基本信息

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

项目摘要

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.

乙醇是一种由生物可再生资源生产的主要商品化学品，主要用于运输燃料。该项目将重点关注改进的催化剂，通过将乙醇转化为乙酸等增值衍生物来扩大乙醇市场。具体来说，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，以获得基本的了解，从而用于设计用于乙酸生产的更具活性和选择性的催化剂。该项目中获得的基础知识将有助于美国生物乙醇工厂的长期可持续性。机理见解还将提供对汽车尾气氧化催化等应用中涉及贵金属的金属-载体相互作用的更好的一般理解。该研究与一项教育计划相结合，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。用于评估原位电荷转移速率及其与表面催化反应的动力学相关性的实验工具数量有限，一直是推进对金属-载体相互作用的理解的主要障碍。已开发出三种可行的光谱技术，以促进 1）金催化剂上吸附氧的原位评估（金表面等离子体共振-紫外可见光谱，即 Au-SPR-UV-vis），2）识别表面反应中间体（调制）激发-相敏检测-漫反射红外傅里叶变换光谱，即ME-PSD-DRIFTS），以及金属之间的电荷转移和支持（调制激发-相敏检测-紫外-可见光谱，即ME-PSD-UV-vis）。该项目将通过研究各种催化剂，同时分离金粒径、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，具有n型半导体特性的载体有利于金纳米颗粒外围的电荷转移，从而促进将乙醇氧化成乙酸的活性物质。总体而言，Au-SPR-UV-vis、ME-PSD-FTIR、ME-PSD-UV-vis、光谱动力学和反应动力学的结合将提供气相乙醇氧化的全面机制视图，以描述观察到的活性和选择性趋势。新知识和技术将有助于设计下一代金氧化催化剂。它们还可转移到其他氧化反应，从而将其适用性扩展到广泛的表面催化反应。研究和教育项目将培养一支训练有素的多元化学生骨干队伍，让他们进入 STEM 学科的劳动力队伍。一项新的课外科学外展活动——EMPower（能量、物质和电力）俱乐部，还将为本科生提供领导机会，同时为来自弱势群体和低收入背景的小学生充当榜样和导师。该倡议将作为催化剂，通过动手活动激发孩子们的好奇心，让他们在有趣的活动中欣赏科学，并激励他们在STEM领域接受教育。该奖项体现了NSF的法定使命，并通过评估认为值得支持。基金会的智力价值和更广泛的影响审查标准。