SOlid frustrated-Lewis-pair single-atom catalysts for efficient photoCATalytic amidation processes

Project Information

SOLCAT

Grant agreement ID: 101152890

DOI

10.3030/101152890

Project closed

EC signature date 24 April 2024

Start date 1 July 2024

End date 30 June 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 172 750,08

Coordinated by

POLITECNICO DI MILANO
Italy

Periodic Reporting for period 1 - SOLCAT (SOlid frustrated-Lewis-pair single-atom catalysts for efficient photoCATalytic amidation processes)

Reporting period: 2024-07-01 to 2026-06-30

Summary of the context and overall objectives of the project

The transition towards a climate-neutral and resource-efficient chemical industry requires new catalytic technologies that reduce waste, minimise the use of critical raw materials, operate under mild conditions and enable efficient manufacturing. Catalysis lies at the heart of this transition, particularly for the production of pharmaceuticals, agrochemicals and other high-value fine chemicals, where current synthetic methods often rely on homogeneous catalysts that are difficult to recover, energy-intensive processes and hazardous reagents.

SOLCAT addressed these challenges by developing heterogeneous photocatalytic systems based on atomically dispersed metal catalysts and carbon nitride materials for sustainable organic synthesis. The project combined the high activity and selectivity of single-atom catalysts with the robustness and recyclability of heterogeneous materials, while exploiting visible light as a renewable energy source for chemical transformations.

The scientific objectives were to design stable catalytic materials with isolated active sites, understand their reaction mechanisms through advanced characterisation and computational modelling, and demonstrate their applicability in scalable synthetic processes. Although the original proposal focused on photocatalytic amidation, the research evolved towards a broader range of strategically important carbon–heteroatom and carbon–carbon bond-forming reactions, enabling the project to generate scientifically mature and impactful results while maintaining its original vision of developing durable, efficient and scalable photocatalytic platforms.

Beyond catalyst development, SOLCAT adopted a "greener-by-design" philosophy, integrating catalyst stability, process efficiency, recyclability, life-cycle assessment and continuous-flow processing into catalyst evaluation. This holistic approach contributes to the European Green Deal, the Chemicals Strategy for Sustainability and Horizon Europe's ambition to accelerate the transition towards safer and more sustainable chemical manufacturing.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Under the supervision of Prof. Vilé, the Fellow developed a portfolio of heterogeneous catalytic systems and established design principles for sustainable photocatalytic synthesis.

The project first demonstrated a copper single-atom catalyst supported on mesoporous carbon nitride for carbon–sulfur bond formation. The catalyst exhibited excellent activity across a broad substrate scope while overcoming one of the major limitations of conventional copper catalysts-deactivation by sulfur-containing compounds. Extensive structural characterisation confirmed true atomic dispersion of copper, while recycling, leaching and mechanistic studies demonstrated exceptional catalyst stability and durability.

A second major achievement was the development of a visible-light palladium single-atom catalyst for carbon–carbon bond formation under mild reaction conditions. Operando X-ray spectroscopy and computational studies revealed how light directly modulates the electronic structure of isolated palladium atoms during catalysis. The work also included techno-economic analysis and life-cycle assessment, demonstrating substantial reductions in catalyst cost, energy consumption, greenhouse-gas emissions and precious-metal use compared with conventional nanoparticle catalysts.

The project further established a metal-free carbon nitride photocatalyst for additive-free halotrifluoromethylation of alkenes under visible light. The catalyst could be recovered and reused multiple times without loss of activity and was successfully transferred from batch operation to continuous-flow processing, achieving an order-of-magnitude increase in productivity while maintaining good performance. This demonstrated the practical potential of heterogeneous photocatalysis for scalable manufacturing.

Complementing the experimental work, the project produced a comprehensive perspective outlining future design principles for chiral single-atom catalysts and a two-part review on greener-by-design fine chemical manufacturing, highlighting how catalyst development should be integrated with sustainable process engineering, digitalisation and continuous manufacturing.

Overall, the project generated several high-quality scientific publications, advanced mechanistic understanding of heterogeneous photocatalysis, strengthened interdisciplinary expertise in catalysis, photocatalysis and flow chemistry, and established a strong scientific foundation for future research on sustainable catalytic technologies.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SOLCAT advances the state of the art by demonstrating that heterogeneous photocatalysts based on atomically dispersed metal sites can simultaneously achieve high catalytic activity, excellent selectivity, long-term stability and practical recyclability. These characteristics address long-standing limitations associated with homogeneous catalysts and nanoparticle-based systems.

The project delivered robust mechanistic understanding by combining advanced spectroscopy, operando experiments and density functional theory calculations, providing molecular-level insight into the behaviour of isolated catalytic sites under reaction conditions. This knowledge establishes general design principles that extend beyond the specific reactions studied and can guide the development of future single-atom photocatalysts.

Importantly, SOLCAT moved beyond laboratory-scale catalyst discovery by integrating sustainability assessment into catalyst development. Life-cycle assessment, techno-economic analysis, catalyst recycling and continuous-flow processing demonstrated that catalyst performance should be evaluated together with environmental, economic and technological criteria. This integrated methodology represents an important contribution towards sustainable-by-design chemical manufacturing.

The project's results provide a platform for future research on photocatalytic synthesis, asymmetric single-atom catalysis and continuous manufacturing. Further uptake will benefit from continued scale-up studies, industrial validation, optimisation of reactor technologies and broader integration with digital process monitoring and advanced manufacturing methods. The generated knowledge also offers opportunities for collaboration with industrial stakeholders interested in sustainable fine-chemical production.