Nucleation and growth studies of nanoporous materials using synchrotron and neutron radiation techniques

Lead Research Organisation: University College London
Department Name: Chemistry

Abstract

Nanoporous aluminosilicate and aluminophosphates are key systems in contemporary materials and catalytic chemistry, with a large number of synthetic microporous framework materials being documented over recent decades. These systems contain, in general, AlO4 and SiO4 or AlO4 and PO4 corner sharing-tetrahedra forming the entire assembly resulting in either one-dimensional chain, two-dimensional layered or three-dimensional open-framework structures with a range of pore dimensions. The main thrust behind the synthesis of new microporous materials, with different pore or cage dimensions and various chemical compositions, is to design novel catalytic systems that introduce specific shape selective and regio-selective properties. These inorganic heterogeneous catalysts are easy to handle, can be recycled and in many instances can be tuned to produce a minimum amount of side-products, and have the potential for use in the large-scale production of chemicals. In this project we propose to carry out a detailed study to understand the formation of these nanoporous systems. The key questions we will address are (1) what are the nucleating species, (2) what is the structure of the nucleating species and does it have any resemblance to the final crystalline product and (3) what is the mechanism involved in the formation of a specific crystalline product under a given conditions. To answer these questions it is necessary to carry out investigations under operating (hydrothermal) conditions and to determine structures that grows rapidly, it is necessary to use time-resolved advanced characterisation techniques. The techniques we propose to use are small-angle X-ray scattering method to determine the size and shape of the particles that are formed during the initial stages of the nucleation processes. Simultaneously we will monitor the crystallising product using wide-angle X-ray scattering. To determine the structure of the non-crystalline particles formed at the initial stages, we will use total scattering methods, in particular X-ray and neutron diffraction methods, applicable to amorphous solids. The information obtained from these studies will provide new information on the mechanism of the network formation prior to crystallisation, which are responsible for the production final crystalline product. We will use the advanced Synchrotron Radiation and Neutron Radiation sources to perform the in situ experiments. By understanding this process we will be able to develop strategy to design synthesis conditions to produce new and novel nanoporous structures.
 
Description We developed new equipments to understand how silica clusters come together to form an ordered network resulting in a 3 dimensional structure, using Synchrotron and Neutron radiation techniques. These solids are widely used in Catalytic processes.
Exploitation Route Already we have reported some of our findings in international and national conferences. The equipment we developed is available for other users of the Diamond and ESRF synchrotron centres
Sectors Chemicals,Energy,Environment

 
Description Our findings, in particular the method development is available for other users of synchrotron techniques to pursue similar research, this includes both industry and academia. In addition, our findings on the chemical process is now used in our group to produce efficient zeolitic solids
Sector Chemicals,Energy,Environment
Impact Types Societal

 
Description Collaboration with Diamond Light source 
Organisation Diamond Light Source
Country United Kingdom 
Sector Academic/University 
PI Contribution We collaborated with Synchrotron Radiation facility at Diamond Light source to investigated the crystallisation process using time-resolved in situ small angle and Wide angle X-ray scattering methods
Collaborator Contribution They provided the beam line and laboratory facilities, data collection strategy and data processing of the collected data
Impact We have recently collected X-ray absorption spectroscopic data at Diamond Light Source. The data being processed for publications
Start Year 2008
 
Description Collaboration with Neutron source 
Organisation Diamond Light Source
Country United Kingdom 
Sector Academic/University 
PI Contribution Beam time at the Synchrotron and Neutron sources were obtained through peer reviewed proposal. We carried out a range of complex in situ experiments to interrogate the species formed during a crystallisation process. We developed protocols to synthesise functional materials and developed in situ methods to carry out the measurements. Analysed the data and published the results in peer reviewed journal and conferences.
Collaborator Contribution collaborating organisation provided beam time and also assisted us with the experimental setup, data acquisition and analysis.
Impact Several forms of outcomes resulted from this collaboration. Firstly, instrument development, through which our group provided the know-how and design for the Synchrotron Sources to use it for other UK or EU users. Second nature of outcome is through presentation in international conferences. Third type of outcome was through publication of our results in peer reviewed Journals and conference books.
 
Description Collaboration with Neutron source 
Organisation European Synchrotron Radiation Facility
Country European Union (EU) 
Sector Academic/University 
PI Contribution Beam time at the Synchrotron and Neutron sources were obtained through peer reviewed proposal. We carried out a range of complex in situ experiments to interrogate the species formed during a crystallisation process. We developed protocols to synthesise functional materials and developed in situ methods to carry out the measurements. Analysed the data and published the results in peer reviewed journal and conferences.
Collaborator Contribution collaborating organisation provided beam time and also assisted us with the experimental setup, data acquisition and analysis.
Impact Several forms of outcomes resulted from this collaboration. Firstly, instrument development, through which our group provided the know-how and design for the Synchrotron Sources to use it for other UK or EU users. Second nature of outcome is through presentation in international conferences. Third type of outcome was through publication of our results in peer reviewed Journals and conference books.