Dielectric properties and electrical conductivity as predictors of catalytic selectivity

多相催化是制造精细化学品、聚合物和其他产品的关键过程之一。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造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，直接观察活性位点和反应中间体的实验挑战，催化表面的扩展和复杂性质使计算建模复杂化，以及缺乏标准化数据报告阻碍了数据科学方法。本项目旨在解决这些问题，利用材料的介电性能和电导率作为：1)在氧化和惰性条件下对催化材料及其表面的实验探针，以及在操作条件下对活性部位的探针；2)计算方法的验证目标，以开发对介电常数和电导率的体、表面和气相贡献的反褶积方法；3)从operando实验中获得高质量的动力学数据来源，旨在支持微动力学模型，旨在描述材料的催化、介电和电性能。该项目最初将涉及二元金属氧化物的实验研究和计算建模，包括但不限于钒、钼、碲和铌的氧化物。作为该项目的一部分，将开发第二代非接触式微波腔仪器，允许在操作条件下精确和可重复地测量电导率。空腔实验将由宽带频率分辨电导率测量补充，也在项目期间开发，为计算建模提供进一步的数据。在该项目的第二阶段，重点将转移到将开发的方法应用于各种钒酸钼的青铜状M1结构。在其他可能的应用中，由于其对丙烯酸的选择性，五元素Mo-V-Te-Nb-O材料的催化性能特别显著。该项目旨在进一步描述催化剂的动态活性表面，通过使用微动力学方法和计算数据模拟介电介电常数和电导率的变化。

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.