Nitridic and Carbidic Interstitial Pd Nanoparticles for Directed Catalysis

用于定向催化的氮化物和碳化物间隙 Pd 纳米颗粒

• 批准号: EP/V000691/1
• 负责人: Peter Wells
• 金额: $ 160.3万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV000691%2F1
• 关键词: Nitridic; Carbidic; Interstitial; Pd; Nanoparticles

In the field of catalysis, supported metal nanoparticles are an important class of materials; they are a convenient way to thrift expensive metals alongside altering the catalytic properties. However, these materials are extraordinarily dynamic and are particularly sensitive to the fluctuation of environmental conditions experienced during reactions. These structural transformations are not benign and they underpin the working function of this class of catalysts. In this study, we will use our expertise in this area to design new active catalysts for environmental protection and the chemicals industry.Without ever realising it, on a daily basis most people will be using or buying products made using supported Pd nanoparticle catalysts. These types of materials are an active component in catalytic converters in car exhausts, and used in the manufacture of many fine chemicals. However, their performance can be affected by the reactant gases they interact with, changing the structure of the Pd NPs, where the Pd atoms become interspersed with H, N or C atoms (depending on the gas present). Understanding these new structures, in terms of their formation and stability during reaction can help understand the influence they have on reactions. For example, we recently reported the formation of nitride interstitial Pd NPs (Nature Catalysis, 2, 157, 2019), and its role in directing the oxidation of ammonia to N2. This reaction is of particular importance for diesel engines where unused ammonia can 'slip' through the exhaust, adding to unwanted emissions. We found that in the presence of the Pd nitride, ammonia is converted to N2, whereas without the nitride phase, there is over oxidation to the pollutant NOx.Our vision is to pre-form interstitial Pd nanoparticle structures and exploit their unique catalytic properties, i.e. they are able to moderate oxidation and hydrogenation chemistry - fundamental to catalysis - to limit over-oxidation and over-reduction products. To achieve this the project must first learn more about how these structures are formed and under what conditions they remain stable. This will be realized by developing element specific spectroscopy that provides direct information on the Pd (XAFS) and the heteroatom environments (MAS NMR) under process conditions. These results will be further supported by DFT modelling studies of realistically sized nanoparticle structures. Ultimately, this will generate a 'rulebook' for how/when these structures are formed and their stability under different conditions (e.g. temperature gas environment).

在催化领域，负载型金属纳米颗粒是一类重要的材料；它们是节省昂贵金属并改变催化性能的便捷方法。然而，这些材料非常动态，并且对反应过程中经历的环境条件的波动特别敏感。这些结构转变不是良性的，它们支撑了此类催化剂的工作功能。在这项研究中，我们将利用我们在该领域的专业知识，为环境保护和化学工业设计新型活性催化剂。在没有意识到的情况下，大多数人每天都会使用或购买由负载型钯纳米颗粒催化剂制成的产品。这些类型的材料是汽车尾气催化转化器的活性成分，并用于制造许多精细化学品。然而，它们的性能可能会受到与之相互作用的反应气体的影响，从而改变 Pd NP 的结构，其中 Pd 原子散布着 H、N 或 C 原子（取决于存在的气体）。了解这些新结构，了解它们在反应过程中的形成和稳定性，有助于了解它们对反应的影响。例如，我们最近报道了氮化物间隙Pd NPs的形成（Nature Catalysis, 2, 157, 2019），及其在引导氨氧化为N2中的作用。这种反应对于柴油发动机来说尤其重要，因为未使用的氨会通过废气“溜走”，增加不必要的排放。我们发现，在存在氮化钯的情况下，氨会转化为氮气，而如果没有氮化物相，则会过度氧化为污染物氮氧化物。我们的愿景是预形成间隙钯纳米颗粒结构并利用其独特的催化性能，即它们能够调节氧化和氢化化学（催化的基础），以限制过度氧化和过度还原产物。为了实现这一目标，该项目必须首先更多地了解这些结构是如何形成的以及它们在什么条件下保持稳定。这将通过开发元素特定光谱来实现，该光谱可提供工艺条件下 Pd (XAFS) 和杂原子环境 (MAS NMR) 的直接信息。这些结果将得到实际尺寸纳米粒子结构的 DFT 建模研究的进一步支持。最终，这将生成一个“规则手册”，说明这些结构如何/何时形成以及它们在不同条件（例如温度气体环境）下的稳定性。

项目成果

Atomistic simulations on the carbidisation processes in Pd nanoparticles

Pd 纳米颗粒碳化过程的原子模拟

• DOI: http://dx.10.1039/d2ra07462a
• 发表时间: 2023
• 期刊: RSC Advances
• 影响因子: 3.9
• 作者: Kordatos A

Towards the Operational Window for Nitridic and Carbidic Palladium Nanoparticles for Directed Catalysis

面向氮化和碳化钯纳米颗粒定向催化的操作窗口

• DOI: http://dx.10.1002/cctc.202300870
• 发表时间: 2023
• 期刊: ChemCatChem
• 影响因子: 4.5
• 作者: Costley