Solid oxide electrolysers (SOECs) are a key class of technology that offers an efficient solution to storing renewable energy. One of the key characteristics of this technology is its ability to reduce both H2O and CO2. Currently, commercial cells are adapted from those made for power generation (i.e. SOFCs) and are not suitable for generating gas of higher quality than syngas due to the limited behaviour of the cells. Electrochemical analyses and gas chromatography were used to examine the ability of SOEC cells to improve gas quality. With the addition of a functional layer to the cathode, we achieved a complementary effect between electrochemical mechanisms taking place at the cathode and catalytic mechanisms involving CO2 and CO methanation. In spite of the fact that the results could be significantly improved, this approach demonstrated the potential for CO2 and H2O co-electrolysis at intermediate temperatures.