Final Report Summary - NANOINSPECTION (Near-Field Spectroscopic Imaging of the Assembly and Working of Nanosheets of Catalytic Porous Materials)
The mission statement of this project is “to obtain new fundamental insights in the formation principles and catalytic functioning of crystalline porous materials”.
This aim is motivated by the urgent need for novel materials with controlled structure, porosity and functionalities that will pave the way towards a more sustainable use of our fossil and renewable resources, including biomass. In order to design new functional materials we need a fundamental understanding of how these materials work. Therefore, the project focuses on the development of new porous model systems and analytical tools for studying these porous catalytic systems at the nanoscale.
During this first phase of the project the main research efforts went into establishing a broad expertise in a) the synthesis of showcase nano-sheet materials and b) the development and application of suitable spectro-microscopic tools to characterize those porous catalyst materials in great detail.
With respect to point a) the research team experienced a steep learning curve, especially in the synthesis of various bulk and thin-films of metal organic frameworks, because the group did not have much expertise in this field. This challenge was successfully tackled by establishing important international collaborations and an active exchange of PhD students with other academic labs. As a result, a large variety of nano-sheet materials have been prepared and investigated. Work focusing on surface-mounted metal-organic frameworks (SURMOFs) and surface-mounted zeolitic imidazolate frameworks (SURZIFs) have resulted in mechanistic insights in the formation, including the synthesis parameters (e.g. metal/linker ratio and metal type) and the framework quality (defect information).
The development of suitable spectro-microscopic tools has seen both an important course correction as well as major leaps forward. The development of AFM-Raman as well as in-situ AFM set-ups has been accomplished and have been utilized in the second phase of the project. Both TERS and SERS have been explored to investigate TERS tip stability towards corrosive environments (of importance when studying catalytic reactions) as well as to determine the kinetics of photo-catalytic active molecules assembled in a monolayer on a gold substrate. Within this framework of analytical tools development two main external events have influenced further directions of the project: i) the availability of commercial AFM-IR systems and ii) the de-facto discontinuation of development efforts towards scanning probe-based X-ray spectroscopy at synchrotron facilities. Extensive feasibility studies and testing from our side have shown promising first results in case i). Case ii) required some corrective actions, namely the widening of the group of showcase materials and the spectro-microscopic tool-set in order to replace the SNXM (scanning near field X-ray microscopy) method. The existing pool of scanning probe methods was therefore complemented by 2-D and 3-D full-field and scanning transmission X-ray microscopy, X-ray Ptychography, Nano-SIMS, atom probe tomography (APT), and single molecule fluorescence (SMF) imaging, all focusing on the characterization of zeolite materials at the nanoscale, down even to the single atom and single molecule level. Clearly, new physicochemical insights have been obtained in the preparation and performance of zeolite-based materials.
During the project new fundamental insights in the formation principles and catalytic functioning of crystalline porous materials has been obtained. And the success of the project is reflected by the publications obtained during the course of this project. A small excerpt of the publication list can be found below.
1. Meirer, F. et al. J. Am. Chem. Soc. 137, 102-105 (2015).
2. Ristanovi, Z., Weckhuysen, B.M. Angew. Chem. Int. Ed. 53, 8556-8558 (2014).
3. Perea, D. E. et al. Nature Commun. 6, 7589 (2015).
4. Schmidt, et al. Angew. Chem. Int. Ed. 55, 11173-11177 (2016).
5. Fu, D. et al. Angew. Chem. Int. Ed. 56, 11217-11221 (2017).
6. Delen, G. et al. Chem. Eur. J. 24, 187-195 (2018).
This aim is motivated by the urgent need for novel materials with controlled structure, porosity and functionalities that will pave the way towards a more sustainable use of our fossil and renewable resources, including biomass. In order to design new functional materials we need a fundamental understanding of how these materials work. Therefore, the project focuses on the development of new porous model systems and analytical tools for studying these porous catalytic systems at the nanoscale.
During this first phase of the project the main research efforts went into establishing a broad expertise in a) the synthesis of showcase nano-sheet materials and b) the development and application of suitable spectro-microscopic tools to characterize those porous catalyst materials in great detail.
With respect to point a) the research team experienced a steep learning curve, especially in the synthesis of various bulk and thin-films of metal organic frameworks, because the group did not have much expertise in this field. This challenge was successfully tackled by establishing important international collaborations and an active exchange of PhD students with other academic labs. As a result, a large variety of nano-sheet materials have been prepared and investigated. Work focusing on surface-mounted metal-organic frameworks (SURMOFs) and surface-mounted zeolitic imidazolate frameworks (SURZIFs) have resulted in mechanistic insights in the formation, including the synthesis parameters (e.g. metal/linker ratio and metal type) and the framework quality (defect information).
The development of suitable spectro-microscopic tools has seen both an important course correction as well as major leaps forward. The development of AFM-Raman as well as in-situ AFM set-ups has been accomplished and have been utilized in the second phase of the project. Both TERS and SERS have been explored to investigate TERS tip stability towards corrosive environments (of importance when studying catalytic reactions) as well as to determine the kinetics of photo-catalytic active molecules assembled in a monolayer on a gold substrate. Within this framework of analytical tools development two main external events have influenced further directions of the project: i) the availability of commercial AFM-IR systems and ii) the de-facto discontinuation of development efforts towards scanning probe-based X-ray spectroscopy at synchrotron facilities. Extensive feasibility studies and testing from our side have shown promising first results in case i). Case ii) required some corrective actions, namely the widening of the group of showcase materials and the spectro-microscopic tool-set in order to replace the SNXM (scanning near field X-ray microscopy) method. The existing pool of scanning probe methods was therefore complemented by 2-D and 3-D full-field and scanning transmission X-ray microscopy, X-ray Ptychography, Nano-SIMS, atom probe tomography (APT), and single molecule fluorescence (SMF) imaging, all focusing on the characterization of zeolite materials at the nanoscale, down even to the single atom and single molecule level. Clearly, new physicochemical insights have been obtained in the preparation and performance of zeolite-based materials.
During the project new fundamental insights in the formation principles and catalytic functioning of crystalline porous materials has been obtained. And the success of the project is reflected by the publications obtained during the course of this project. A small excerpt of the publication list can be found below.
1. Meirer, F. et al. J. Am. Chem. Soc. 137, 102-105 (2015).
2. Ristanovi, Z., Weckhuysen, B.M. Angew. Chem. Int. Ed. 53, 8556-8558 (2014).
3. Perea, D. E. et al. Nature Commun. 6, 7589 (2015).
4. Schmidt, et al. Angew. Chem. Int. Ed. 55, 11173-11177 (2016).
5. Fu, D. et al. Angew. Chem. Int. Ed. 56, 11217-11221 (2017).
6. Delen, G. et al. Chem. Eur. J. 24, 187-195 (2018).