Periodic Reporting for period 1 - PATHWAYS (Photoinduced ultrafast carriers and thermal effects within metasurfaces for light-driven catalysis)
Período documentado: 2024-05-16 hasta 2025-05-15
Catalysis lies at the heart of modern industrial chemistry. It enables the production of more than 85% of chemical goods essential to our daily life, from plastics and pharmaceutical products to fertilisers, and contributes to trillions of euros in annual revenue. Yet, the chemical processes behind these products remain highly energy-intensive. They often require extreme operating conditions (pressures over 100 atm, temperatures above 400 °C), and are typically fed by fossil fuel combustion. As a result, the chemical industry is one of the world’s largest energy consumers (~2.5% of global use), and emits close to 1.5% of global greenhouse gases (around one gigaton per year). Greening, intensifying and enhancing selectivity of these large-scale processes by powering them under milder conditions is a critical challenge for climate neutrality and industrial sustainability.
One promising way towards this urgent transformation is plasmonic photocatalysis, an emerging approach that uses light and metallic nanostructures to drive chemical reactions. These nanoscale, ‘plasmonic’, materials concentrate light into extremely small volumes, offering a local environment where reactions can proceed by light excitations at pressures and temperatures far below those that typify traditional reactors. By modifying how energy is delivered to the reaction sites, they can change rates and open new, otherwise inaccessible reactivity channels.
Despite exceptional promise, current plasmonic photocatalysis methods face two major limitations: the inability to control the spatial arrangement of nanostructures, and the use of continuous-wave illumination, which restricts the operation regime to the steady-state.
In this context, the Marie Skłodowska-Curie Action PATHWAYS seeks to enable a paradigm shift in catalysis by introducing a new class of photocatalysts with tailored properties in space and time, driven by ultrashort light pulses to unlock reaction pathways that offer superior efficiency and selectivity.
The core objective of the project is to introduce new theoretical approaches that can predict how pulsed light excitation of engineered metal nanostructures influences reaction rates, selectivity, and energy use. To achieve this, the project is developing new multi-scale, multiphysics models that describe energy flows through nanostructured catalysts – from light absorption, to hot carrier generation, to energy transfer and reaction activation on the metal surface. These models are intended to guide experiments and set the foundation for data-driven design of photocatalysts, exploring how tailored ultrafast optical pulses can improve reaction outcomes beyond what is possible with traditional continuous-wave illumination. Beyond the immediate scope and duration of the project, the long-term vision of PATHWYAS includes scientific, technological, and societal impact, stemming from the development of new photocatalytic platforms offering sustainable, cost- and energy-effective alternatives to traditional approaches.
One promising way towards this urgent transformation is plasmonic photocatalysis, an emerging approach that uses light and metallic nanostructures to drive chemical reactions. These nanoscale, ‘plasmonic’, materials concentrate light into extremely small volumes, offering a local environment where reactions can proceed by light excitations at pressures and temperatures far below those that typify traditional reactors. By modifying how energy is delivered to the reaction sites, they can change rates and open new, otherwise inaccessible reactivity channels.
Despite exceptional promise, current plasmonic photocatalysis methods face two major limitations: the inability to control the spatial arrangement of nanostructures, and the use of continuous-wave illumination, which restricts the operation regime to the steady-state.
In this context, the Marie Skłodowska-Curie Action PATHWAYS seeks to enable a paradigm shift in catalysis by introducing a new class of photocatalysts with tailored properties in space and time, driven by ultrashort light pulses to unlock reaction pathways that offer superior efficiency and selectivity.
The core objective of the project is to introduce new theoretical approaches that can predict how pulsed light excitation of engineered metal nanostructures influences reaction rates, selectivity, and energy use. To achieve this, the project is developing new multi-scale, multiphysics models that describe energy flows through nanostructured catalysts – from light absorption, to hot carrier generation, to energy transfer and reaction activation on the metal surface. These models are intended to guide experiments and set the foundation for data-driven design of photocatalysts, exploring how tailored ultrafast optical pulses can improve reaction outcomes beyond what is possible with traditional continuous-wave illumination. Beyond the immediate scope and duration of the project, the long-term vision of PATHWYAS includes scientific, technological, and societal impact, stemming from the development of new photocatalytic platforms offering sustainable, cost- and energy-effective alternatives to traditional approaches.
During the reporting period, the project has made substantial progress towards its scientific objectives, through the activities carried out at the Associated Partner Institution (Rice University, Houston, TX, United States). The core effort during the outgoing phase (Months 1 to 12) has focussed on developing a new numerical framework to simulate photocatalytic processes occurring at the surface of photoexcited plasmonic nanostructures.
An original modelling approach was implemented, integrating the key physical mechanisms – nanoscale electromagnetic interactions, thermal transport, and electronic excitations – into a unified, self-consistent numerical platform based on the Finite Element Method. The numerical model enables simultaneous resolution across temporal, spatial and energy scales, and captures real-time dynamics of light-driven chemical events. It computes key experimental observables, such as reaction rates, effective activation energies, and temperatures, thus enabling direct comparison with measured data. The platform proposed makes the model adaptable to a range of nanostructured photochemical systems, including various chemical reactions, illumination conditions, nanostructure shape, size and configuration. It can also be extended to incorporate more sophisticated descriptions of metal-molecule interactions derived from ab-initio calculations.
A second major scientific activity during this reporting period focussed on exploring how ultrashort optical pulses can be used to modulate catalytic efficiency by controlling the temporal distribution of the incoming light. A combination of tailored experiments and simulations successfully validated this approach, demonstrating the potential of ultrafast light pulses in photocatalysis. The results disclosed a strongly nonlinear dependence of the reaction rate on the pulse temporal distribution, which was interpreted with a newly developed model as resulting from the temporal modulation of the reaction effective energy barrier through light-activated nonthermal pathways.
As a whole, these achievements represent a valuable step forward in the implementation of PATHWAYS. They also provide a solid foundation for the next stages of the project, which will build on the multiscale numerical platform developed and the insights gained into pulse-induced nonlinearities to carry out the planned investigations in the second phase of the Action.
An original modelling approach was implemented, integrating the key physical mechanisms – nanoscale electromagnetic interactions, thermal transport, and electronic excitations – into a unified, self-consistent numerical platform based on the Finite Element Method. The numerical model enables simultaneous resolution across temporal, spatial and energy scales, and captures real-time dynamics of light-driven chemical events. It computes key experimental observables, such as reaction rates, effective activation energies, and temperatures, thus enabling direct comparison with measured data. The platform proposed makes the model adaptable to a range of nanostructured photochemical systems, including various chemical reactions, illumination conditions, nanostructure shape, size and configuration. It can also be extended to incorporate more sophisticated descriptions of metal-molecule interactions derived from ab-initio calculations.
A second major scientific activity during this reporting period focussed on exploring how ultrashort optical pulses can be used to modulate catalytic efficiency by controlling the temporal distribution of the incoming light. A combination of tailored experiments and simulations successfully validated this approach, demonstrating the potential of ultrafast light pulses in photocatalysis. The results disclosed a strongly nonlinear dependence of the reaction rate on the pulse temporal distribution, which was interpreted with a newly developed model as resulting from the temporal modulation of the reaction effective energy barrier through light-activated nonthermal pathways.
As a whole, these achievements represent a valuable step forward in the implementation of PATHWAYS. They also provide a solid foundation for the next stages of the project, which will build on the multiscale numerical platform developed and the insights gained into pulse-induced nonlinearities to carry out the planned investigations in the second phase of the Action.
The research activities conducted during this reporting period of the project have focussed on a rather unexplored regime for photocatalysis, which typically uses continuous-wave illumination instead of pulsed light. This positions the results of the project significantly beyond the current state of the art.
In particular, the development of a novel multiphysics numerical platform constitutes a key innovation output. It offers a flexible and modular virtual laboratory, with the potential to become predictive for various photocatalytic processes. Its strength lies in the generality of its architecture: each component can be independently modified or extended, allowing for seamless incorporation of increasingly accurate and sophisticated descriptions of the underlying processes. Compared to the state of the art, the platform reduces numerical limitations, offers a toolset for designing tailored photocatalysts, and possibly foster broader applications across nanophotonics and light-driven chemistry. In addition, the discovery of nonlinear effects using pulses further expands the current understanding of how temporal shaping of light can influence reaction dynamics. These results open new avenues for research into out-of-equilibrium regimes of light-driven catalysis and could stimulate further theoretical and experimental investigations.
To ensure uptake and continued progress, the next steps will include applying the model to different materials and reactions, and benchmarking results against more conventional, steady-state approaches. This will be relevant to validating the findings, and expanding the approach by tuning on demand the thermal and nonthermal contributions to the reaction pathways upon suitable changes of the properties of the incoming light. Beyond the immediate scope of the project and towards technological impact, engaging industry stakeholders would be instrumental to translate the effects of light temporal shaping using pulses into technologies.
In particular, the development of a novel multiphysics numerical platform constitutes a key innovation output. It offers a flexible and modular virtual laboratory, with the potential to become predictive for various photocatalytic processes. Its strength lies in the generality of its architecture: each component can be independently modified or extended, allowing for seamless incorporation of increasingly accurate and sophisticated descriptions of the underlying processes. Compared to the state of the art, the platform reduces numerical limitations, offers a toolset for designing tailored photocatalysts, and possibly foster broader applications across nanophotonics and light-driven chemistry. In addition, the discovery of nonlinear effects using pulses further expands the current understanding of how temporal shaping of light can influence reaction dynamics. These results open new avenues for research into out-of-equilibrium regimes of light-driven catalysis and could stimulate further theoretical and experimental investigations.
To ensure uptake and continued progress, the next steps will include applying the model to different materials and reactions, and benchmarking results against more conventional, steady-state approaches. This will be relevant to validating the findings, and expanding the approach by tuning on demand the thermal and nonthermal contributions to the reaction pathways upon suitable changes of the properties of the incoming light. Beyond the immediate scope of the project and towards technological impact, engaging industry stakeholders would be instrumental to translate the effects of light temporal shaping using pulses into technologies.