In adherence to the previously outlined criteria, we constructed the f-EPC reactor, integrating stainless steel and PTFE (polytetrafluoroethylene) frames (160 mm × 95 mm × 10 mm) to house the electrodes within an insulating and solvent-resistant environment. This design ensures that the electrodes can be firmly compressed, and the inter-electrode distance can be finely tuned by utilizing serpentine-shaped PTFE gaskets of varying thickness (0.1 mm -0.5 mm), thereby allowing a cell volume of 0.28-1.4 mL. Liquids can be introduced directly into the reactor using Super Flangeless Nuts (PEEK, 1/4-28 Flat bottom, for 1/16"OD). Evidently, at least one of the electrodes must be transparent to ensure effective light penetration into the reactor. Thus, we implemented an FTO (fluorine-doped tin oxide) glass slab coated with a thin layer of Pt nanoparticles via a previously reported procedure to boost its catalytic activity to proton reduction (14b, 14c).