Measuring diffusion of small molecules in heterogeneous catalysts

在与格拉斯哥大学的一项新合作中，Johnson Matthee正在赞助EPSRC工业案例博士生，使用(I)反应测试，(Ii)光学光谱，(Iii)电子显微镜和(Iv)准弹性中子散射(QENS)的组合来研究高比表面积非均相催化剂中催化事件的基本方面。QENS是一种测量固体扩散的强大技术。有时，它也被用来研究催化体系，主要是沸石，但数据库并不大。鉴于非弹性中子散射在研究非均相催化剂方面的最新进展，以及支持这项工作的样品环境的相关开发，现在是时候通过应用QENS将这些研究扩大到包括扩散组分。这些研究将为以下基本领域提供新的信息：原子之间的干扰现象、沸石的晶格扭曲、短程有序、原子或分子经历随机运动等。了解分子如何在多相催化剂中扩散对于许多不同的过程，如选择性催化还原、甲醇合成和二氧化碳捕获具有重要意义。扩散的一般领域也与工艺技术和排放控制技术相联系。QENS技术在评估工作催化剂/材料中物种扩散方面的发展是新颖的，它将提供对反应动力学的更好理解，从而可以将其与催化剂性能联系起来。这名学生将主要位于哈威尔研究中心，该中心位于牛津郡的卢瑟福·阿普尔顿实验室。此外，每年，学生将被期望在公司的英国研究中心之一进行安置。

In a new collaboration with the University of Glasgow, Johnson Matthey are sponsoring an EPSRC Industrial CASE Ph.D. studentship to use a combination of (i) reaction testing, (ii) optical spectroscopy, (iii) electron microscopy and (iv) quasi-elastic neutron scattering (QENS) to investigate fundamental aspects of catalytic events in high surface area heterogeneous catalysts.QENS is a powerful technique for measuring diffusion in solids. On occasion, it has been used for studying catalytic systems, principally with zeolites, but the database is not large. Given recent advances in the application of inelastic neutron scattering to investigate heterogeneous catalysts and the associated development of sample environment to support that work, it is now timely to extend those investigations to include a diffusional component via application of QENS. Such studies will provide new information on the following fundamental areas: interference phenomena between atoms, lattice distortions of the zeolite, short-range order, atoms or molecules experiencing stochastic motions, etc. Understanding how molecules diffuse within heterogeneous catalysts is of great importance to a number of diverse processes, such as selective catalytic reduction, methanol synthesis and CO2 capture. The general area of diffusion also connects to the disciplines of process technology and emission control technology. The development of the QENS technique for assessing diffusion of species in working catalysts/materials is novel and will provide an improved understanding of reaction kinetics, which can then be linked to catalyst performance. The student will be primarily located at the Harwell Research Complex, which is located at the Rutherford Appleton Laboratory in Oxfordshire. In addition, each year, the student will be expected to spend a placement at one of the Company's UK research centres.