Computational Modelling of the Formation and Stability of Supported Particles of Catalytic Importance
Lead Research Organisation:
CARDIFF UNIVERSITY
Department Name: Chemistry
Abstract
Since modern society demands a higher quality of life base on efficient technology and clean energy, contemporary scientists focus on new materials with particular properties performing under environmental friendly conditions. Structures of less than 100 nano-meters in size present different properties from those of bulk materials. This scale has opened new research boundaries in a growing field, with wide-ranging implications. For example, current industries use nano-materials during the fabrication of a large number of everyday-products. In chemical industries these fine particles are commonly dispersed metals on support materials reducing the cost and waste yields during product manufacture. However, scientists follow primarily a ''mix and try'' approach for the synthesis because of the complexity of the formation process and stability nano-structures, which are affected by multiple parameters, such as temperature, pressure and metal precursor.
Particle performance is dependent on their size and shape. Therefore we aim to identify computationally the thermodynamic and kinetic descriptors affecting the growth and stability of metal particles supported on specific surfaces. This project will allow us to unravel the effects of the support, the metal and the size of nano-particles while considering e.g. particles shape and diffusion across the surface, which will help to understand processes such as sintering and deactivation of the catalyst under working conditions. In particular, we propose to combine a number of late transition metals with well-characterised surfaces because of their importance in industrial catalysis and the extensive experimental data available.
The first goal of this challenging task is to understand the mechanism needed to build stable clusters from where the particle will grow. We will study the particles' interaction and diffusion on the surface and the feasibility of nearby particles to agglomerate. The second major goal is to identify the parameters modifying the growth processes along particular directions leading to different particle shapes such as sheets, wires, flakes. The reactivity of these structures will also be evaluated against common molecules such as molecular oxygen and water as both are present in oxidation reactions and in energy harvesting systems. The activity towards the activation and dissociation of molecular oxygen is important for reducing industrial waste related with oxidation processes. The last goal is to combine the previous results in a kinetic model to predict a durable nano-structure with applications in industry and energy technologies.
We will carry out this investigation in an effective and reliable way by combining a range of informatics tools which provide atomic-level resolution of the nano-structures and the supporting surface with accurate details e.g. oxidation state of the metal at the interface with the support. The combinations of these computational methods will allow us to study the factors controlling nucleation, growth and the shape of the supported metallic particles. The results will be validated by our experimental partners in the Cardiff Catalysis Institute and at the UK Catalysis Hub. With the success of this innovative research, we will provide detailed understanding of the parameters controlling the sintering of supported structures leading to undesirable properties e.g. loss of catalytic performance. The knowledge derived from this research is applicable to many chemical industries and academic researchers. We will disseminate the work across a wide range of fields. Within Cardiff Catalysis Institute and the assistance provided by association with the UK Catalysis Hub, we will outreach and engage the public which will be of importance in a project on such a topical theme.
Particle performance is dependent on their size and shape. Therefore we aim to identify computationally the thermodynamic and kinetic descriptors affecting the growth and stability of metal particles supported on specific surfaces. This project will allow us to unravel the effects of the support, the metal and the size of nano-particles while considering e.g. particles shape and diffusion across the surface, which will help to understand processes such as sintering and deactivation of the catalyst under working conditions. In particular, we propose to combine a number of late transition metals with well-characterised surfaces because of their importance in industrial catalysis and the extensive experimental data available.
The first goal of this challenging task is to understand the mechanism needed to build stable clusters from where the particle will grow. We will study the particles' interaction and diffusion on the surface and the feasibility of nearby particles to agglomerate. The second major goal is to identify the parameters modifying the growth processes along particular directions leading to different particle shapes such as sheets, wires, flakes. The reactivity of these structures will also be evaluated against common molecules such as molecular oxygen and water as both are present in oxidation reactions and in energy harvesting systems. The activity towards the activation and dissociation of molecular oxygen is important for reducing industrial waste related with oxidation processes. The last goal is to combine the previous results in a kinetic model to predict a durable nano-structure with applications in industry and energy technologies.
We will carry out this investigation in an effective and reliable way by combining a range of informatics tools which provide atomic-level resolution of the nano-structures and the supporting surface with accurate details e.g. oxidation state of the metal at the interface with the support. The combinations of these computational methods will allow us to study the factors controlling nucleation, growth and the shape of the supported metallic particles. The results will be validated by our experimental partners in the Cardiff Catalysis Institute and at the UK Catalysis Hub. With the success of this innovative research, we will provide detailed understanding of the parameters controlling the sintering of supported structures leading to undesirable properties e.g. loss of catalytic performance. The knowledge derived from this research is applicable to many chemical industries and academic researchers. We will disseminate the work across a wide range of fields. Within Cardiff Catalysis Institute and the assistance provided by association with the UK Catalysis Hub, we will outreach and engage the public which will be of importance in a project on such a topical theme.
Planned Impact
The ability to design and optimise supported nano-structures will have impact in a variety of areas, from academic and industrial research to the general public. In the short term, the outcomes of this project will benefit academic researchers (as outlined in the "academic beneficiaries" section), as well as chemical industries involving nano-structures either in the product manufacture or waste management. In a longer term, the understanding of the particle formation and stability on a support will provide strong basis for the design of nano-structures with applications in a widespread range of fields such as healthcare, sustainable materials, information handling, and energy harvesting and storage, being the wide society the ultimately end-user.
The knowledge resulting from the project will have an impact on materials and catalytic scientists, who will value not only the atomic level properties of the catalyst but also the methodology and scientific techniques developed during this project. We will contribute to the development of well-defined structures on-demand, which will make a distinctive contribution to the whole domain of catalysis. Our work will align to this priority and will interact strongly with the Cardiff Catalysis Institute and the UK Catalysis Hub, which will assist with the dissemination of the work and the development of impact.
Although our research is based on a solid base of fundamental understanding of the design, synthesis and performance of new catalytic materials, the outcomes will be of commercial interest related with the necessity of optimised particles for specific applications. For example, mono-dispersed nano-structures and their stability are areas of great strategic importance to the chemical industry with the potential for fostering long-term industrial engagement. Indeed, given progress with the science proposed, we anticipate subsequent stages involving the design of efficient devices, their scale-up and testing in direct collaboration with industrial users.
In the long-term, the proposed research programme will also assist the energy and environmental security. This ultimate goal will be achieved by enabling the development of novel technology devices with potential applications for improving energy harvesting and waste reduction.
The development of technical expertise during the project will impact on scientists in a variety of fields, as well as benefit the PI's, PDRA and PhD career development.
The knowledge resulting from the project will have an impact on materials and catalytic scientists, who will value not only the atomic level properties of the catalyst but also the methodology and scientific techniques developed during this project. We will contribute to the development of well-defined structures on-demand, which will make a distinctive contribution to the whole domain of catalysis. Our work will align to this priority and will interact strongly with the Cardiff Catalysis Institute and the UK Catalysis Hub, which will assist with the dissemination of the work and the development of impact.
Although our research is based on a solid base of fundamental understanding of the design, synthesis and performance of new catalytic materials, the outcomes will be of commercial interest related with the necessity of optimised particles for specific applications. For example, mono-dispersed nano-structures and their stability are areas of great strategic importance to the chemical industry with the potential for fostering long-term industrial engagement. Indeed, given progress with the science proposed, we anticipate subsequent stages involving the design of efficient devices, their scale-up and testing in direct collaboration with industrial users.
In the long-term, the proposed research programme will also assist the energy and environmental security. This ultimate goal will be achieved by enabling the development of novel technology devices with potential applications for improving energy harvesting and waste reduction.
The development of technical expertise during the project will impact on scientists in a variety of fields, as well as benefit the PI's, PDRA and PhD career development.
Publications
Roldan A
(2018)
Frontiers in first principles modelling of electrochemical simulations
in Current Opinion in Electrochemistry
Morteo-Flores F
(2020)
Biomass hydrodeoxygenation catalysts innovation from atomistic activity predictors.
in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
Lu X
(2021)
Kinetic and mechanistic analysis of NH3 decomposition on Ru(0001), Ru(111) and Ir(111) surfaces.
in Nanoscale advances
Lu X
(2020)
Mechanistic study of hydrazine decomposition on Ir(111).
in Physical chemistry chemical physics : PCCP
Lu X
(2024)
Ammonia Cracking on Single-Atom Catalysts: A Mechanistic and Microkinetic Study
in Applied Catalysis A: General
Guadix-Montero S
(2021)
Controlling the Selectivity of Supported Ru Nanoparticles During Glycerol Hydrogenolysis: C-O vs C-C Cleavage
in ChemCatChem
Francis S
(2022)
Ostwald ripening microkinetic simulation of Au clusters on MgO(0 0 1)
in Applied Surface Science
Engel J
(2019)
The influence of support materials on the structural and electronic properties of gold nanoparticles - a DFT study.
in Physical chemistry chemical physics : PCCP
Engel J
(2020)
The influence of oxygen vacancy and Ce 3+ ion positions on the properties of small gold clusters supported on CeO 2-x (111)
in Journal of Materials Chemistry A
Description | We have found a methodology to predict the morphology of small-medium Au nanoparticles on MgO, graphite and CeO2, which was the main objective of the project. We have also found a very weak interaction of Au and C, medium interaction on MgO and strong interaction with CeO2. It this interaction that defines the morphology of the particles, i.e. flat and pyramid. Indeed, on MgO and C, the Au structures are flat while on CeO2 is a pyramid in agreement with the cohesive/adhesion energies ratio. Ostwald ripening has been also studied and found not strong barriers in absence of stabilisers on MgO and C supports. |
Exploitation Route | We are preparing further proposals, this time in full collaboration with experimentalists, to study the effect on the particles morphology interacting with gas and liquid under reaction conditions. This will have an important impact in industries employing nanocatalysts as it will help to determine their lifetime. |
Sectors | Chemicals Energy Environment |
Description | The last findings originated from this project led to a collaboration with Johnson Matthey, which fund a PhD student to continue with subsequent investigations. In collaboration with Johnson Matthey we developed proof-of-concept of a bottom-up sintering model of supported nanocatalysts. |
First Year Of Impact | 2019 |
Sector | Chemicals |
Impact Types | Cultural Economic |
Description | Computational Modelling of the Formation and Stability of Supported Particles of Catalytic Importance |
Amount | € 2,500 (EUR) |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 02/2018 |
End | 05/2018 |
Title | Biomass HDO Catalysts Innovation from Atomistic Activity Predictors - data |
Description | This dataset was produced un course of a density functional theory (DFT) study exploring the relationship between twelve transition metals (TMs) properties, as catalysts, and their affinity for hydrogen and oxygen, as key species in the valorisation of biomass. The Excel file (.xlsx) contains the hydrogen and oxygen adsorption energies (in eV), and different transition properties such as surface energy (in J m-2), work function, d-band width, centre (in Å) |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
URL | https://research.cardiff.ac.uk/converis/portal/detail/Dataset/104938086?auxfun=&lang=en_GB |
Title | Pioneering simulations in electrochemistry: the frontiers in first principles modelling |
Description | This DataSet contains information regarding the interaction of water molecules with metallic surfaces. In particular, we have reported the adsorption energy of a monolayer of water molecules on fcc metals: Au, Ag, Cu, Pt, Pd, Ni. The dataset contains also the work-function values for naked, polarisable salvation continuum model (PCM), single and double water layer together with the PCM. It is compared with standard metal standard reduction potentials. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Title | Research data from "The Influence of Support Materials on the Structural and Electronic Properties of Gold Nanoparticles - A DFT Study" |
Description | These data were produced in course of a dispersion corrected density functional theory (DFT-D) study investigating the effect of commonly used support materials (MgO, C, CeO2) on small gold particles with up to 19 atoms. The Excel file (.xlsx) contains the energies of the supported metal clusters (in eV), the energies of the isolated clusters (in eV), adsorption energies (in eV), cohesion energies (in eV), detachment energies (in eV), average cluster-surface distances (in Å), average gold-gold distances (in Å), and charge of the metal clusters (in e). These values were used to create the plots shown in the article. The mismatch_calculator.py Python 3 script was used to calculate the geometric mismatch between the cluster interface and support surface. |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | Yes |
Title | Research data from "The influence of oxygen vacancy and Ce3+ ion positions on the properties of small gold clusters supported on CeO2-X(111)" |
Description | This dataset was produced in course of a dispersion corrected density functional theory (DFT-D(U)) study investigating the effect of oxygen vacancies in CeO2 on small gold particles . The Excel file (.xlsx) contains the vacancy position, average cluster-surface distances (in Å), average gold-gold distances (in Å), charge of the metal clusters (in e), number of Ce3+ ions, and presence of Au-Ce bands. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
URL | https://research.cardiff.ac.uk/converis/portal/detail/Dataset/98139066?auxfun=&lang=en_GB |
Description | HPC-Europa3 Student Exchange with Barcelona University (2019 - 2019) |
Organisation | University of Barcelona |
Country | Spain |
Sector | Academic/University |
PI Contribution | We established a solid collaboration with the team of Federico Calle-Vallejo to work on the solvation of nanostructures. |
Collaborator Contribution | Federico guided the visiting student for 3 months. |
Impact | Established international collaborative work. |
Start Year | 2019 |
Description | HPC-Europa3 Student Exchange with Genoa University |
Organisation | University of Genoa |
Department | Department of Chemistry and Industrial Chemistry |
Country | Italy |
Sector | Academic/University |
PI Contribution | A PhD student from my group visited Prof Riccardo Ferrando for almost 3 months funded by the HPC-Europa3. We established a collaboration where we provide DFT studies on metallic nanoparticles of realistic size. |
Collaborator Contribution | The PhD student developed skill in interatomic potentials by simulating supported nanostructures, in line with her thesis, under the supervision of a worldwide expert on the topic. |
Impact | Publication under preparation |
Start Year | 2018 |
Title | IPSA |
Description | Software to measure the symmetry of regular and irregular structures, independently of their nature. |
Type Of Technology | Software |
Year Produced | 2022 |
Open Source License? | Yes |
Impact | Useful to classify supported nanoparticles in heterogeneous catalysts, e.g., to identify active sites. |
URL | https://link.springer.com/10.1007/s10910-022-01423-x |
Title | Mismatch calculator |
Description | A script to find the strain between a 2D interface formed by two different materials, e.g. metal and oxide support. |
Type Of Technology | Webtool/Application |
Year Produced | 2019 |
Open Source License? | Yes |
Impact | No much used yet. |
URL | https://github.com/Alberto-Roldan-Martinez/Mismatch_Calculator |
Description | Cardiff Catalysis Institute Conference |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | We participate with posters and talks to the Cardiff Catalysis Institute annual conference. The topics presented are related to catalysts design, clean hydrogen and environment, biomass conversion as well as their implementation for a circular economy. |
Year(s) Of Engagement Activity | 2016,2017,2018,2019,2020,2021 |
Description | Cardiff Chemistry Conference |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | The School of Chemistry organises an open event every year to expose scientific progress in the field. We commonly present posters in the field of clean energy, sustainable environment and circular economy. |
Year(s) Of Engagement Activity | 2017,2018,2019,2020,2021 |
Description | Invited Lectures |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | I held invited talks in Xiamen (China) and Queretaro (Mexico) in the departments of Chemistry. The titles are "Accelerating Catalytic Process Understanding using Computer Simulations" and "Global Faculty Week" respectively. |
Year(s) Of Engagement Activity | 2017 |
Description | Invited talk |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Policymakers/politicians |
Results and Impact | <100 attendees discussing future technologies in environmental and manufacturing field |
Year(s) Of Engagement Activity | 2017 |
Description | Seminars / Lectures |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Study participants or study members |
Results and Impact | I have promoted research taking place in my group in seminars and lectures to a specialised public. The duration of the talks depended on the length of the workshop there were a follow up with questions and answers. |
Year(s) Of Engagement Activity | 2017 |