Devices were then evacuated for 10 mins and filled with pure CO2 gas (> 1.01 bar). This was repeated three times to fully exchange the N2 gas (from the glovebox environment in which the cells were prepared) with CO2. The electrochemical cells were placed in an incubator oven (SciQuip Incu-80S) at 35 °C. This temperature was consistent with similar literature systems, enabling accurate comparison. The constant current was applied across the cell and the increase and decrease in pressure in the device, upon release and capture, respectively, was monitored using a pressure transducer (Omega, PX309-030A5V) which was connected to the potentiostat as an external device, enabling simultaneous electrochemistry and cell gas pressure measurements.