Dielectric properties and electrical conductivity as predictors of catalytic selectivity

多相催化是精细化学品、聚合物和其他产品生产中的关键过程之一。然而，尽管我们对多相催化的理解取得了进展，但通过系统设计而不是偶然发现来创建多相催化剂的目标仍然难以实现。这是由于几个挑战，包括催化在空间和时间上的多尺度性质，在直接观察活性中心和反应中间体方面的实验挑战，催化表面的扩展和复杂的性质使计算模拟复杂化，以及缺乏标准化的数据报告阻碍数据科学的方法。本项目旨在通过使用材料的介电性质和导电性来解决这些问题：1)在氧化和惰性条件下的催化材料及其表面的实验探测器，以及在操纵面条件下的活性中心的探测器；2)计算方法的验证目标，以开发一种对介电常数和电导率的体相、表面和气相贡献进行反卷积的方法；以及3)来自旨在描述材料的催化以及介电和电学性质的操纵面实验的高质量动力学数据的来源。项目最初将涉及二元金属氧化物的实验研究和计算模拟，包括但不限于钒、钼、碲和Nb的氧化物。作为该项目的一部分，将开发第二代非接触式微波腔仪器，使其能够精确和可重复地测量工作条件下的电导率。该项目还将开发宽带频率分辨电导率测量，为计算建模提供进一步的数据。在该项目的第二阶段，重点将转移到将所开发的方法应用于各种钒钼酸盐的青铜状M1结构上。在其他可能的应用中，五元Mo-V-Te-Nb-O材料的催化性能尤其显著，因为它对丙烯酸的选择性。本项目旨在通过使用微动力学方法和计算数据模拟操纵面介电常数和电导率的变化，进一步描述催化剂的动态活性表面。

Heterogeneous catalysis is one of the key processes in the manufacture of fine chemicals, polymers, and other products. However, despite the progress in our understanding of heterogeneous catalysis, the goal of creating a heterogeneous catalyst by systematic design rather than serendipitous discovery remains elusive. This is due to several challenges, including the multi-scale nature of catalysis in both space and time, experimental challenges in direct observation of active sites and reaction intermediates, the extended and complex nature of catalytic surfaces complicating computational modelling, as well as the lack of standardised data reporting hindering data-scientific approaches.This project aims to address these issues by using the dielectric properties and the electrical conductivity of materials as: 1) an experimental probe of the catalytic material and its surface under oxidative and inert conditions, as well as a probe of the active site under operando conditions; 2) a validation target for computational methods to develop a method for the deconvolution of bulk, surface, and gas-phase contributions to the dielectric permittivity and electrical conductivity; and 3) a source of high-quality kinetic data from operando experiments designed to underpin a microkinetic model, with the aim to describe the catalytic as well as dielectric and electrical properties of the material.The project will initially involve the experimental investigation and computational modelling of binary metal oxides, including but not limited to the oxides of vanadium, molybdenum, tellurium, and niobium. A second-generation contactless microwave cavity instrument will be developed as part of this project, allowing for a precise and reproducible measurement of the electrical conductivity under operating conditions. The cavity experiments will be supplemented by a broadband frequency-resolved conductivity measurement, also developed during the project, to supply further data for computational modelling.In the second stage of this project, the focus will shift to applying the developed methods to the bronze-like M1 structure of various molybdenum vanadates. The catalytic performance of the quinary Mo-V-Te-Nb-O material is particularly remarkable due to its selectivity to acrylic acid, among other possible applications. This project aims to further describe the dynamic active surface of the catalyst, by modelling the changes in the operando dielectric permittivity and electrical conductivity using microkinetic approaches and computational data.