Exploring the use of bioethanol for high-temperature electrolysis of water

Abstract

The production of green hydrogen is currently facing a challenge due to its growing role as a chemical intermediate or energy vector. Thus, it is unsurprising that there is a strong interest in improving current technologies and developing new approaches to reduce energy demand for producing pure H2. Taking advantage of the thermodynamic characteristics of solid oxide electrochemical cells, we devised a new cell that could simultaneously reduce water and oxidize bioethanol, and as a result to achieve green hydrogen at very low electric power energy consumption. This approach was demonstrated by developing a symmetrical electrolyte-supported cell. The selected electrolyte was LSGM, which showed interesting conductive properties and was free of electronic leaks. An exsolved perovskite in combination with doped ceria (i.e. LSCN-CGO) was selected for cathode and anode for its promising electrocatalytic and redox properties. This cell demonstrated excellent stability over 450 h of testing and an excellent power-saving operation at a current density of 0.8 A cm−2 at 0.25 V. Results of the physico-chemical measurements evidenced a very stable morphology and very interesting redox properties of the investigated materials composing the cell. Considering these characteristics and the negligible amount of carbon observed in the anode, the complete perovskite designed as LSCN-CGO/LSGM/LSCN-CGO is promising for producing green H2 with the aid of bioethanol.