Deionized water (Simplicity UV water purification system, Merck Millipore, 18.2 MΩ•cm @ 25 °C), 2-butanol (99%, Sigma Aldrich), and oxygen (99.999% vol., Messer) were used as reagents to conduct liquid-phase catalytic tests in both flow and batch conditions. The testing was performed on a Phoenix Flow Reactor system (ThalesNano), comprising a Gas Module, a Liquid-Gas Mixer, an HPLC pump (Azura P4.1S, Knauer), and a Pressure Module. The scheme and depiction of the system are shown in the Supplementary Information (Figure ). The powder with a grain size > 65 um was packed in a tubular cartridge (CatCart®, 70 mm, 0.76 mL, ThalesNano), and inserted into a stainless-steel cartridge holder inside the furnace of the reaction system. After the reactor set-up was assembled, the same start-up procedure was followed for each catalytic test. The system was pressurized under oxygen at the desired pressure and heated up to the desired temperature with a heating rate of 10 °C per minute. A 1% vol. (0.11 M) aqueous solution of 2-butanol, previously degassed in an ultrasonic bath for 30 seconds, was then flown at the desired flow rate. The liquid phase was collected discontinuously in an ice-cooled, custom-made glass cold trap and was analysed with an offline GC-FID, while the uncondensed gases exited from the top of the cold trap and were analysed by an online GC-FID/TCD. The details of the GC analyses are described in section S2. At the end of each catalytic test, the 2-butanol solution feed was stopped, and deionized distilled water was fed to the reactor for a few hours. Then, the liquid feed was stopped again, keeping only the gaseous oxygen feed for another few hours. The furnace was turned off and, once it had reached ambient temperature, the system was depressurized. After that, the gas feed was stopped, and the reactor was disconnected from the system and put inside an oven at 120 °C for overnight drying.