The e-ODH button cell consisted of a 2.5 cm outer diameter (OD) Scandia Stabilized Zirconia electrolyte support (Hionic TM ) with LSM/LSM-GDC cathode printed area of 1.78 cm OD received from Nexceris via fuelcellmaterials.com. The anode powder was prepared by mixing 50-50 wt.% of the LSF catalyst and GDC powder purchased from fuelcellmaterials.com (SKU: 111102). The anode ink, prepared by mixing 60 wt.% of the anode powder with α-Terpineol (Sigma-Aldrich), was screen-printed (0.7-inch diameter) on the blank side to form the anode electrode of the button cell. The anode and cathode electrodes were fitted with a silver mesh using silver paint (50980332, Fisher Scientific) with a 0.25 mm OD silver wire attached to the mesh as the current collecting lead. The button cell was then assembled on a specially designed and fabricated 2.54 cm OD alumina tube which reduces the gas residence time with the anode side facing the tube and the cathode side exposed to air (Figure in Supplementary Information). The button cell was sealed onto the alumina tube using Aremco 617 Sealant and slowly cured in a tube furnace to 850°C at 3.5°C/min and held for 15 minutes followed by the same cool-down rate to the testing temperature of 700°C. The silver leads were connected to a Gamry interface 5000P