When less is more: Enhancement of green hydrogen production and efficiency by using electrodes with ultra-low platinum loadings

Abstract

Sulfur dioxide depolarized electrolysis (SDE) is a promising technology for cost-effective green hydrogen production that can be used for the storage of intermittent renewable energies used to power the electrolyzer. The obtained hydrogen can be stored and used as a source for producing electricity in a fuel cell. However, high platinum loadings (around 2 mgPt cm−2) in the anode and cathode electrodes significantly contribute to the overall cost of the electrolyzer. This study aimed to optimize both electrodes using the electrospray technique for the deposition of ultra-low Pt loadings. The electrodes achieved a total platinum loading as low as 0.4 mgPt cm−2 (0.3 mgPt cm−2 for the anode and 0.1 mgPt cm−2 for the cathode), an 80 % reduction compared to common platinum loadings. This reduction not only increased the hydrogen production rate (18 mL min−1 with optimized electrodes vs. 4.7 mL min−1 with non-optimized electrodes) but also decreased the production of hydrogen sulfide in the cathode, resulting in a hydrogen stream with higher purity. Overall, this study demonstrates the potential of electrospray for achieving low platinum loadings and improving the efficiency of SDE for green hydrogen production.