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.

面对日益减少的石油储量和日益增长的可持续性需求，社会面临的最大挑战之一是为不断增长的人口提供能源。一个有希望的策略是从生物质能中获取能源。具体来说，据估计，到2030年，美国每年可以生产超过10亿吨的干生物质，如果适当地转化为可用燃料，其能量含量相当于当前石油消耗量的46%。然而，许多将生物质转化为燃料和化学品的过程需要添加氢气。不幸的是，目前从可再生资源中供应氢气的方法效率低下且成本高昂，阻碍了生物质经济的发展。生物质水相重整（APR）是一种很有前途的制氢方法。具体来说，在APR中，一部分生物质通过催化剂转化为H2，催化剂是一种能够在不消耗自身的情况下进行化学反应的材料。尽管前景看好，但迄今为止，APR的产氢率令人失望，这表明需要提高APR催化剂的效率。设计新催化剂的第一步需要了解现有催化剂的功能。在这里，克莱姆森大学的雷切尔·盖特曼博士和佐治亚理工学院的卡斯滕·西弗斯博士正在结合最先进的模型和光谱来研究APR反应的三个关键步骤：1)氢的去除；Ii)一氧化碳的生成；水和一氧化碳反应生成氢气和二氧化碳。由于APR产生的二氧化碳将用于种植新的生物质，因此APR是一个“碳中性”过程。更广泛的影响包括将本科生，特别是女性和代表性不足的少数民族纳入基础化学和应用化学的有意义的探索中。研究成果也将在佐治亚州亚特兰大的罗伯特·c·威廉姆斯造纸博物馆展出。在化学部化学催化项目的资助下，克莱姆森大学的Rachel Getman博士和佐治亚理工学院的Carsten Sievers博士将多尺度建模和operando光谱相结合，以提供有关生物质衍生的氧合物在负载Pt催化剂上转化为氢和二氧化碳的水相重整（APR）的活性位点和机制的基本见解。具体来说，该项目侧重于选择性和非选择性脱氢、脱碳和水煤气转换（WGS）如何受到水作为溶剂、共吸附水和旁观物质以及支持性质的影响。新的见解将使研究人员能够设计改进的催化剂和优化工艺条件。建模研究包括将密度泛函理论的方法与经典分子动力学相结合，以便同时考虑化学键的断裂和形成以及溶剂中液态水分子的热运动。主要的实验技术是衰减全反射红外光谱，它可以探测浸入反应物溶液中的催化剂表面的物质。实验和理论工作高度结合。例如，计算和测量的表面物质的振动频率及其形成和转化的速率常数进行了比较，从而能够开发与实验观测相一致的模型。ppi大力支持女性和少数族裔学生的参与。此外，这个项目的成果将在佐治亚州亚特兰大的罗伯特·c·威廉姆斯造纸博物馆展出，并通过生物精炼选修课向更广泛的观众展示。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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

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