High-performance alkaline water electrolyzers based on Ru-perturbed Cu nanoplatelets cathode

• Published in: Nature communications Vol. 14; no. 1; p. 4680
• Main Authors: Zuo, Yong, Bellani, Sebastiano, Ferri, Michele, Saleh, Gabriele, Shinde, Dipak V., Zappia, Marilena Isabella, Brescia, Rosaria, Prato, Mirko, De Trizio, Luca, Infante, Ivan, Bonaccorso, Francesco, Manna, Liberato
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04-08-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/146; 147/135; 147/137; 147/143; 639/301/299; 639/4077; 639/638/77/886; Alkaline water; Capital expenditures; Catalysts; Cathodes; Copper; Current density; Expenditures; Humanities and Social Sciences; Hydrogen evolution reactions; Iron compounds; Metals; multidisciplinary; Nanoparticles; Nickel compounds; Platelets (materials); Production costs; Ruthenium; Science; Science (multidisciplinary); Stainless steel; Stainless steels; United States > US
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-40319-5

Alkaline electrolyzers generally produce hydrogen at current densities below 0.5 A/cm
2
. Here, we design a cost-effective and robust cathode, consisting of electrodeposited Ru nanoparticles (mass loading ~ 53 µg/cm
2
) on vertically oriented Cu nanoplatelet arrays grown on metallic meshes. Such cathode is coupled with an anode based on stacked stainless steel meshes, which outperform NiFe hydroxide catalysts. Our electrolyzers exhibit current densities as high as 1 A/cm
2
at 1.69 V and 3.6 A/cm
2
at 2 V, reaching the performances of proton-exchange membrane electrolyzers. Also, our electrolyzers stably operate in continuous (1 A/cm
2
for over 300 h) and intermittent modes. A total production cost of US$2.09/kg
H2
is foreseen for a 1 MW plant (30-year lifetime) based on the proposed electrode technology, meeting the worldwide targets (US$2–2.5/kg
H2
). Hence, the use of a small amount of Ru in cathodes (~0.04 g
Ru
per kW) is a promising strategy to solve the dichotomy between the capital and operational expenditures of conventional alkaline electrolyzers for high-throughput operation, while facing the scarcity issues of Pt-group metals.
Achieving high-efficiency alkaline water electrolyzer operating at large current densities remains a critical challenge. Here the authors report Ru nanoparticle-perturbed Cu nanoplatelets as cathode for hydrogen evolution reaction coupled with stainless steel anode in alkaline electrolyzer with high performance, long-term stability and relatively low-capital expenditures.