Developing Wide Line Solid State NMR as a Novel Analytical Approach to understand Metals in Catalytic Technology for Fuel Cells

开发宽线固态核磁共振作为一种新颖的分析方法来了解燃料电池催化技术中的金属

• 批准号: EP/G00367X/1
• 负责人: John Hanna
• 金额: $ 18.69万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG00367X%2F1
• 关键词: Developing; Wide; Line; Solid; State

The Stern report stresses that that the drive to more sustainable energy and the introduction of new technologies in this area must be urgently pursued. Fuel cells have a key role to play in the future energy economy. However, one of central components in many fuel cells is the precious metal electrodes which are very expensive, such that their longevity and high expense often limit fuel cell economics. Understanding the structure of the precious metal nanoparticles that make up these catalytic layers is often difficult due to the highly heterogeneous, disordered nature of these materials. This project will develop wide line solid state NMR of precious metal nuclei as a new characterisation tool for such nanoparticles. It will bring together a group with a long track record of developing new materials applications of solid state NMR and an internationally-leading industrial group that are developing fuel cell catalyst technologies. The project attempts to fulfil the philosophy of the Sainsbury Review to get the core academic science base interacting more directly with industry. Traditionally, platinum catalysts have been used exclusively for low temperature fuel cells due to their overall adequate activity and stability for three key reactions of interest. More recently, alloying of platinum with various other metals has shown improvements in both activity and selectivity leading to a diverse range of catalysts for specific reactions. Currently, more advanced research concepts are focussed on nano core-shell materials, where a platinum (or platinum alloy) shell is deposited onto a different core (e.g. palladium) to give both activity (through electronic modification) and cost benefits. Of the metals of interest, platinum is key as this is the basis for most current active formulations. Palladium is of increasing interest as recent reports have indicated that alloying palladium with base metals such as iron can increase activity for some reactions to that of platinum. Also, it has been extensively used as a core for platinum. Rhodium has not been extensively investigated for fuel cell catalysis, but it does show promise as a promoter for platinum for the electro-oxidation of ethanol. In addition, rhodium is the key catalytic metal for a large range of gas-phase reactions, including the CO-NOx reaction in automotive catalysis and the reforming of hydrocarbon fuels to give hydrogen. A characterisation approach that combines traditional analysis techniques (e.g. XRD, TEM, XPS) along with determination of the catalytic activity will be employed. This data will be merged with the new and potentially unique information that will be provided by solid state NMR. A fully multinuclear approach will be employed to examine 1H (to elucidate surface speciation and proton mobility, the latter via relaxation and pulsed field gradient measurements), as well as 13C and 27Al of the support materials. However the clear focus of the work here will be developing NMR of the metals directly. There has already been progress made on 195Pt which has shown that in such heterogeneous systems very broad spectral lines indeed can be encountered such that traditional pulsed approaches are not possible. With the use of field-sweep approaches accurate lineshapes of even very broad lines can be recorded. This project will take this philosophy, develop it further for 195Pt and take on the very much more challenging task of examining 103Rh and 105Pd. The reports of solid state NMR from the latter two nuclei are extremely scarce providing an indication of their difficulty. However by the use of the state of the art NMR equipment available (e.g. field sweep, very high magnetic field) and the construction of a probe optimised for the static observation of these nuclei it is anticipated that significant progress can be made in observing such nuclei. This would provide a new analytical probe of these technologically important materials.

斯特恩报告强调，必须立即推动这一领域的可持续能源发展和新技术的引进。燃料电池在未来的能源经济中发挥着关键作用。然而，许多燃料电池的核心部件之一是非常昂贵的贵金属电极，因此它们的寿命和高费用常常限制燃料电池的经济性。由于这些材料的高度异质性、无序性，了解构成这些催化层的贵金属纳米颗粒的结构通常很困难。该项目将开发贵金属核的宽线固态核磁共振，作为此类纳米颗粒的新表征工具。它将汇集一个在开发固态核磁共振新材料应用方面拥有悠久历史的集团和一个正在开发燃料电池催化剂技术的国际领先工业集团。该项目试图实现《塞恩斯伯里评论》的理念，让核心学术科学基础与工业界更直接地互动。传统上，铂催化剂专门用于低温燃料电池，因为它们对三个关键反应具有足够的活性和稳定性。最近，铂与各种其他金属的合金化显示出活性和选择性的改进，从而产生了用于特定反应的各种催化剂。目前，更先进的研究概念集中在纳米核壳材料上，其中铂（或铂合金）壳沉积在不同的核（例如钯）上，以提供活性（通过电子修饰）和成本效益。在感兴趣的金属中，铂是关键，因为它是大多数当前活性配方的基础。钯越来越受到人们的关注，因为最近的报告表明，将钯与铁等贱金属制成合金可以增加铂的某些反应的活性。此外，它还被广泛用作铂的核心。铑在燃料电池催化方面尚未得到广泛研究，但它确实显示出作为乙醇电氧化铂的促进剂的前景。此外，铑还是多种气相反应的关键催化金属，包括汽车催化中的CO-NOx反应以及碳氢化合物燃料重整制取氢气。将采用将传统分析技术（例如 XRD、TEM、XPS）与催化活性测定相结合的表征方法。该数据将与固态 NMR 提供的新的、可能独特的信息合并。将采用完全多核方法来检查 1H（以阐明表面形态和质子迁移率，后者通过弛豫和脉冲场梯度测量）以及支撑材料的 13C 和 27Al。然而，这里工作的明确重点将是直接开发金属的核磁共振。 195Pt 已经取得了进展，表明在这种异构系统中确实可以遇到非常宽的谱线，因此传统的脉冲方法是不可能的。通过使用场扫描方法，甚至可以记录非常宽的线的精确线形。该项目将秉承这一理念，进一步发展 195Pt，并承担检查 103Rh 和 105Pd 的更具挑战性的任务。后两个原子核的固态核磁共振报告极其稀少，这表明了它们的难度。然而，通过使用最先进的核磁共振设备（例如场扫描、极高磁场）以及针对这些原子核的静态观察而优化的探头结构，预计在观察这些原子核方面可以取得重大进展。这将为这些技术上重要的材料提供新的分析探针。

项目成果

Multinuclear Solid-State NMR Investigation of Hexaniobate and Hexatantalate Compounds.

• DOI: 10.1021/acs.inorgchem.6b00345
• 发表时间: 2016-06
• 期刊: Inorganic chemistry
• 影响因子: 4.6
• 作者: G. Deblonde;Cristina Coelho-Diogo;A. Chagnes;G. Cote;Mark E. Smith;J. Hanna;D. Iuga;C. Bonhomme

Insight into the Partitioning and Clustering Mechanism of Rare-Earth Cations in Alkali Aluminoborosilicate Glasses

• DOI: 10.1021/acs.chemmater.1c01352
• 发表时间: 2021-04
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Hrishikesh Kamat;Fu Wang;Kristian E. Barnsley;J. Hanna;A. Tyryshkin;A. Goel

Crystal Chemistry of Vanadium-Bearing Ellestadite Waste Forms.

• DOI: 10.1021/acs.inorgchem.8b01160
• 发表时间: 2018-07
• 期刊: Inorganic chemistry
• 影响因子: 4.6
• 作者: Yanan Fang;S. Page;Gregory J Rees;M. Avdeev;J. Hanna;T. White

Natural abundance (25)Mg solid-state NMR of mg oxyanion systems: a combined experimental and computational study.

毫克氧阴离子系统的自然丰度 (25)Mg 固态 NMR：实验和计算相结合的研究。

• DOI: 10.1002/chem.200900346
• 发表时间: 2009
• 期刊: Chemistry (Weinheim an der Bergstrasse, Germany)
• 作者: Cahill LS

Adsorption of HF on gibbsite calcined at various temperatures: A solid-state NMR study of low-level fluorinated systems

不同温度下煅烧的三水铝石上 HF 的吸附：低含量氟化体系的固态核磁共振研究

• DOI: 10.1016/j.jpcs.2021.110355
• 发表时间: 2022
• 期刊: Journal of Physics and Chemistry of Solids
• 影响因子: 4
• 作者: Agbenyegah G