Northwestern team develops solid acid electrochemical cell for the production of hydrogen from ammonia
Researchers at Northwestern University, with colleagues from SAFCell, Inc, have demonstrated the production of high-purity hydrogen by thermal-electrochemical decomposition of ammonia at an intermediate temperature of 250 ˚C. A paper on their work is published in the journal Joule.
The process is enabled by use of a solid-acid-based electrochemical cell (SAEC) in combination with a bilayered anode, comprising a thermal-cracking catalyst layer and a hydrogen electrooxidation catalyst layer.
Cs-promoted Ru on carbon nanotubes (Ru/CNT) serves as the thermal decomposition catalyst, and Pt on carbon black mixed with CsH2PO4 is used to catalyze hydrogen electro-oxidation.
Cells were operated at 250 ˚C with humidified dilute ammonia supplied to the anode and humidified hydrogen supplied to the counter electrode.
A current density of 435 mA/cm2 was achieved at a potential of 0.4 V and ammonia flow rate of 30 sccm. With a demonstrated Faradic efficiency for hydrogen production of 100%, the process yields hydrogen at a rate of 1.48 molH2/gcath.
Lim et al. (2020) “Solid Acid Electrochemical Cell for the Production of Hydrogen from Ammonia,” Joule doi: 10.1016/j.joule.2020.10.006