Prior to starting the ALD procedure, a 10 min IR background spectrum was recorded. Subsequently, 10 ALD cycles were performed by consecutive dosing of TDMAH and D2S via electromagnetic valves. In every ALD cycle, TDMAH was first dosed continuously over a course of 5 min with a duty cycle of 0.0085 (opening time 125 ms per 15 s dosing, pressure was always below 5 x 10 -6 mbar) (i), followed by 2 min of pumping (ii), dosing D2S (1 x 10 -6 mbar) over a course of 10 min (iii), and finally 2 min of pumping (iv). TDMAH was dosed from the vapor phase above the neat compound in a glass crucible at room temperature (vapor pressure is 0.1 Torr at 48°C, Strem) and D2S was dosed from a gas reservoir (p(D2S) = 1 mbar). Each ALD cycle (steps (i) to (iv)) was completed in 19 min. Recording of IR spectra and gas dosing was synchronized using LabView. Accordingly, 19 spectra with an acquisition time of 1 min were recorded during each ALD cycle. For the in-situ IRAS experiments regarding the first ALD half cycle on the pristine cobalt oxides, we first recorded a 10 min IR background spectrum. Next, we exposed the sample to very small amounts of TDMAH by applying short gas pulses (opening time of the electromagnetic valve: 50x 10 ms, then 10x 25 ms, finally 10x 50 ms pulses on CoO(100); 50x 15 ms pulses, then 10x 25 ms, finally 10x 50 ms pulses on CoO(111)). As a result, we obtained a very low TDMAH dose per pulse, which allowed us to decouple the measurement time from the exposure. After each pulse of TDMAH, we recorded a 1 min IR spectrum.