Controlled ensemble size and elucidation of structure-sensitivity: a new approach in nitride catalysis

大多数工业化学过程使用催化剂来提高反应进行的速度或有利于特定的产物。因此，催化剂可以大大节省用于大规模工艺的能源，并减少产生的废物量。在应用的催化剂中，多相催化剂是最实用的，因为它们易于从产品流中分离。该项目将结合金属氮化物的合成和应用进展，这是一类具有有趣和独特性质的新兴异相催化剂。所采取的方法是控制分散在宿主基质内的活性中心的大小和组成。控制集合大小已被证明是一个强大的方法与其他类别的催化剂。我们建议开发具有增强氨合成活性的新材料，氨合成是全球范围内至关重要的反应，其中一些金属氮化物已经显示出工业应用的潜在兴趣。我们还计划瞄准另外两个重要过程的高活性-氨分解，这是可再生能源应用的潜在清洁氢源，以及氨氧化，在化学品合成中很重要。后者是一个特别具有挑战性的目标，需要在活性中心内结合不同功能的催化剂设计。我们的计划结合了催化剂合成路线的发展，这将用于控制催化位点的大小和元素组成，以及广泛的催化剂测试，包括在工业相关条件下进行的反应。

Most industrial chemical processes use catalysts to enhance the rate at which a reaction proceeds or to favour a specific product. Catalysts thus lead to significant savings in the energy used for large scale processes and a reduction in the amount of waste generated. Amongst the catalysts applied, heterogeneous catalysts are the most practical due to the ease of their separation from product streams. This project will combine synthetic and application based advances to metal nitrides which are an emerging class of heterogeneous catalyst with interesting and distinctive properties. The approach taken is to exert control over both the size and composition of active centres dispersed within a host matrix. Controlled ensemble size has proven to be a powerful approach with other categories of catalysts. We propose to develop novel materials with enhanced activity for ammonia synthesis, a vitally important reaction on a global scale for which some metal nitrides have already shown activity of potential interest for industrial application. We also plan to target high activities in two other important processes - ammonia decomposition, which is a potential clean hydrogen source for renewable energy applications, and ammoxidation, important in chemicals synthesis. The latter is a particularly challenging target which requires catalyst design that combines different functionalities within active centres. Our programme combines the development of catalyst synthesis routes, which will be used to control the size and elemental composition of the catalytic sites with extensive catalyst testing, involving reactions performed under industrially relevant conditions.