Elevated-temperature bio-ethanol-assisted water electrolysis for efficient hydrogen production

Steam electrolysis over solid oxide electrolysis cells (SOECs) is a promising technique to store renewable power (such as solar and wind power) into hydrogen, and bio-ethanol-assisted steam electrolysis not only increases energy conversion efficiency but also store bio-mass energy into valuable fuels. This study developed SOEC-type reactors for conducting ethanol-assisted water electrolysis for the first time. Conventional catalytic steam reforming of ethanol for hydrogen production consumes a lot of heat and includes a complicated process, while the ethanol-assisted water electrolysis can achieve thermoneutral operation at the electrolysis potential of 0.36 V and generate heat at the electrolysis potentials of above 0.36 V, simultaneously obtaining pure hydrogen from cathode chamber by one step. Micro-reformer constructed by loading fibrous catalysts within channeled anode supports performed efficient ethanol reforming to facilitate fuel oxidation on anode and hence promote steam electrolysis on cathode. Employing Ni-based materials for both anode and cathode enables the co-sintering of three layers of SOEC components, resulting in low cell resistances and stable electrolysis at a record high current density of 3.0 A cm-2 under a low overall cell voltage of less than 1.3 V. Therefore, this study has demonstrated an efficient way to generate green hydrogen energy from renewables.

Automated summary

This study developed SOEC-type reactors for ethanol-assisted water electrolysis, which efficiently converts bio-ethanol into pure hydrogen energy. By loading catalysts in the anode support, efficient reforming of ethanol and fuel oxidation are achieved, along with steam electrolysis. The use of Ni-based materials for both anode and cathode results in low resistance and stable electrolysis performance. Therefore, this study has demonstrated an efficient method for generating green hydrogen energy from renewable sources.