Development of novel approaches toward energy-efficient photochemistry in continuous flow

The research outlined in this thesis was directed towards the development of novel methodologies to perform photochemical transformations in continuous flow. A meticulous approach was adopted to design reactor systems that would optimize photon utilization, thereby enhancing productivity, while simultaneously minimizing energy consumption.
The work described in this manuscript can be divided into three main research lines. First, a focus was placed on the development of photochemical reactors capable of concentrating photons gathered from sunlight. A large scale reactor was first built to produce chemicals in an autonomous fashion under fluctuating solar irradiation. Sensors provide a feedforward system to adapt the flows of reagents to the incoming light and provide a consistent product output. Then, a second reactor design is presented using luminescent coatings. This smaller scale system is used for fast prototyping and rapid screening of reaction conditions.
In the second part of this thesis, the emphasis shifts toward CO2 conversion assisted by solar simulated light. Special attention is paid to the reactor design to aid the characterization of the different catalysts. Various catalysts are tested and optimized for carbon monoxide or methane production. The product is then used and valorised into follow-up transformations.
Finally, the third segment of this thesis shifts its focus toward the development of laboratory-scale photoreactors. The design of 3D printable flow and batch systems provides tools to perform efficient and reproducible photochemical transformations. Combining ray-tracing simulations and chemical actinometry experiments, the reactors were extensively characterized.