A glass photoreactor (LTF MR-LAB-V) was immersed into a heated oil reactor casing with a quartz window. The backplate of the casing contained ceramic heating rods to heat the oil (CAS 68083-14-7) to a set temperature using a PID controller. The pressure was regulated with an automated back pressure regulator developed in-house. An overflow tube and vessel are present to prevent pressure buildup in the tank. Irradiation was provided by an array of four white chip-on-board LEDs (CXB3590, cool white, 86 W electrical input power per chip) placed at 2 cm from the window. Gases were supplied through mass flow controllers (MFC, Bronkhorst max. 10 mln/min, volume at normal conditions; 0 °C and 1 atm), connected to a supply at 5 bars, and could be co-fed into the reactor. Stainless-steel Swagelok and IDEX fittings in combination with FEP tubing (OD 1.6 mm) were used to connect the distinct parts. The analysis was conducted with a gas chromatograph (see Supplementary Information).