Collaborative Research: Combining Operando Spectroscopy and Multi-Scale Modeling to Elucidate the Mechanism of Aqueous Phase Reforming of Oxygenates

合作研究：结合原位光谱学和多尺度建模来阐明含氧化合物水相重整的机制

• 批准号: 1764304
• 负责人: Carsten Sievers
• 金额: $ 31.77万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1764304&HistoricalAwards=false
• 关键词: Collaborative; Research; Combining; Operando; Spectroscopy

One of the greatest challenges facing society is supplying energy to an ever-increasing population in the face of declining petroleum reserves and an increasingly need for sustainability. One promising strategy is to derive energy from biomass. Specifically, it is estimated that by 2030, the U.S. can produce more than 1 billion metric tons of dry biomass per year, which would have an energy content equivalent to 46% of the current oil consumption, if properly converted into usable fuels. However, many processes for converting biomass into fuels and chemicals require the addition of hydrogen gas. Unfortunately, present methods for supplying hydrogen gas from renewable resources are inefficient and costly, impeding the expansion of the biomass economy. The aqueous phase reforming (APR) of biomass is a promising strategy for producing hydrogen gas. Specifically, in APR, a part of the biomass is converted into H2 over a catalyst, which is a material that enables a chemical reaction without being consumed itself. Although promising, hydrogen yields from APR have thus far been disappointing, indicating a need to improve the efficiencies of APR catalysts. The first step in designing new catalysts entails understanding the function of the existing catalysts. Here, Dr. Rachel Getman of Clemson University and Dr. Carsten Sievers of the Georgia Institute of Technology are combining state-of-the-art modeling and spectroscopy to study the three key steps of the APR reaction: i) the removal of hydrogen; ii) generation of carbon monoxide; and iii) reaction of water and carbon monoxide to form hydrogen and carbon dioxide. Since the carbon dioxide produced in APR will be used to grow new biomass, APR is a "carbon-neutral" process. Broader impacts involve the inclusion of undergraduates, especially women and underrepresented minorities, into meaningful explorations of fundamental and applied chemistry. Research results are also being presented at the Robert C. Williams Paper Museum of Papermaking in Atlanta, GA.With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Rachel Getman from Clemson University and Dr. Carsten Sievers from the Georgia Institute of Technology are combining multiscale modeling and operando spectroscopy to provide fundamental insight regarding the active sites and mechanism of the Aqueous Phase Reforming (APR) of biomass-derived oxygenates to hydrogen and carbon dioxide over supported Pt catalysts. Specifically, the project is focused on how selective and non-selective dehydrogenation, decarbonylation, and Water Gas Shift (WGS) are affected by water as a solvent, co-adsorbed water and spectator species, and the nature of support. The new insight will enable researchers to design improved catalysts and optimize process conditions. Modeling studies involve combining methods in density functional theory with classical molecular dynamics, in order to simultaneously incorporate the breaking and forming of chemical bonds and the thermal motions of the liquid water molecules in the solvent. The main experimental technique is attenuated total reflection IR spectroscopy, which allows for probing surface species on catalysts that are immersed in a solution of the reactant. Experimental and theoretical efforts are highly integrated. For example, calculated and measured vibrational frequencies of surface species and rate constants for their formation and conversion are compared, enabling the development of models that are consistent with experimental observations. The PIs are strongly supporting the participation of female and underrepresented minority students. Further, the results from this project are presented to a broader audience through a display at the Robert C. Williams Paper Museum of Papermaking in Atlanta, GA as well as through a biorefining elective.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.

面对社会面临的最大挑战之一是面对石油储备的下降以及对可持续性的需求越来越多，为不断增加的人口供应能源。一种有希望的策略是从生物质中得出能量。具体而言，据估计，到2030年，美国每年可以生产超过10亿吨的干生物量，如果适当地转换为可用的燃料，则能源含量等于当前石油消耗的46％。但是，将生物量转化为燃料和化学物质的许多过程都需要添加氢气。不幸的是，目前从可再生资源提供氢气的方法效率低下且昂贵，阻碍了生物量经济的扩大。生物质的水相改革（APR）是产生氢气的有前途的策略。具体而言，在APR中，一部分生物质通过催化剂转化为H2，这是一种材料，可以使化学反应而不会被消耗。尽管有希望的是，迄今为止，APR的氢产量令人失望，这表明需要提高APR催化剂的效率。设计新催化剂的第一步是了解现有催化剂的功能。在这里，克莱姆森大学的雷切尔·盖特曼（Rachel Getman）博士和佐治亚理工学院的Carsten Sievers博士正在结合最先进的建模和光谱法，以研究APR反应的三个关键步骤：i）去除氢； ii）一氧化碳产生； iii）水和一氧化碳形成氢和二氧化碳的反应。由于APR生产的二氧化碳将用于生长新的生物质，因此APR是“碳中性”过程。更广泛的影响涉及将本科生，尤其是妇女和代表性不足的少数群体纳入有意义的基本化学和应用化学的探索。研究结果还在佐治亚州亚特兰大的罗伯特·C·威廉姆斯纸博物馆造纸博物馆提出。与化学部的化学催化计划的资助，克莱姆森大学的雷切尔·盖特曼博士和乔治亚技术研究所的卡斯滕·西弗斯博士一起，将多个模型和操作的阶段与现有的机制相结合，并提供了现有的（现有的阶段），并在现有的阶段（当前的机制）（现有机制）生物质衍生的氧化能超过受支持的PT催化剂，从而氧化为氢和二氧化碳。具体而言，该项目的重点是选择性和非选择性脱氢，脱邻化和水气转移（WGS）如何受水作为溶剂，共同吸附的水和观众物种的影响，以及支持的性质。新的见解将使研究人员能够设计改进的催化剂并优化过程条件。建模研究涉及将密度功能理论中的方法与经典的分子动力学结合，以同时结合化学键的破裂和形成，以及溶剂中液态水分子的热运动。主要的实验技术是减弱的总反射红外光谱法，它允许在浸入反应物溶液中的催化剂上探测表面物种。实验和理论努力是高度整合的。例如，比较了表面物种的计算和测量的振动频率，并比较了其形成和转化的速率常数，从而使模型的发展与实验观测一致。 PI强烈支持女性和代表性不足的少数民族学生的参与。此外，该项目的结果通过在佐治亚州亚特兰大的罗伯特·C·威廉姆斯纸博物馆的展示以及通过生物培训的选修课中向更广泛的受众介绍。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识和更广泛影响的评估来通过评估来获得支持的。

项目成果

Active sites and effects of co-adsorbed H2O on isolated methanol dehydrogenation over Pt/γ-Al2O3

• DOI: 10.1016/j.jcat.2021.08.027
• 发表时间: 2021-09-02
• 期刊: JOURNAL OF CATALYSIS
• 影响因子: 7.3
• 作者: Hare, Bryan J.;Carcamo, Ricardo A. Garcia;Sievers, Carsten
• 通讯作者: Sievers, Carsten