Waste Biomass Helps Unlock Hydrogen and Formate in Lower-Energy Electrolysis

(National Research Council of Science and Technology/Phys.Org) ... A research team has developed a high-efficiency electrochemical system that simultaneously produces hydrogen and value-added chemicals using glycerol, a low-cost, abundant byproduct of biodiesel production. The findings are published in Joule.

The study is significant in that it replaces the anodic oxygen evolution reaction (OER), a key bottleneck in conventional water electrolysis, thereby reducing the overall cell voltage and improving energy efficiency and expanding the scope of electrochemical conversion technologies.

Hydrogen is gaining attention as a key energy source in the carbon-neutral era, and various water electrolysis technologies have been actively developed for its eco-friendly production. However, conventional electrolysis systems suffer from limitations due to the oxygen evolution reaction (OER) at the anode, which requires high energy input and exhibits slow kinetics, thereby reducing overall process efficiency and economic feasibility.

To address these challenges, the research team, led by Juchan Yang, principal researcher at Korea Institute of Materials Science (KIMS), in collaboration with Professor Ji-Wook Jang, Hankwon Lim, and Hosik Lee of Ulsan National Institute of Science and Technology (UNIST), developed an anion exchange membrane water electrolysis (AEMWE) system that utilizes glycerol as an alternative feedstock and applies the glycerol oxidation reaction (GOR) at the anode as a paired electrolysis strategy.

Glycerol, an abundant and low-cost byproduct of biodiesel production, enables the reaction to proceed at lower energy input compared to conventional water electrolysis.

The team also employed a copper–cobalt-based non-precious metal catalyst, achieving high catalytic activity and stability without relying on expensive noble metals. The system demonstrated a high current density of 110 mA/cm² at a relatively low cell voltage of 1.31 V.

Notably, this technology enables the simultaneous production of hydrogen and chemical feedstocks such as formate, distinguishing it from conventional water electrolysis processes that produce only hydrogen.

The system achieved a high selectivity of approximately 96% toward the target chemical product (formate), and stable performance was confirmed in a large-area electrolyzer cell of 79 cm², demonstrating its potential for practical industrial applications.

This technology represents a promising electrochemical platform that simultaneously produces hydrogen and chemical feedstocks using waste bio-resources, offering both reduced production costs for green hydrogen and improved resource utilization efficiency.

In particular, it presents a carbon-neutral production strategy that integrates energy and chemical manufacturing processes, with the potential to replace conventional separated production systems.

Furthermore, the system is scalable to continuous operation and megawatt (MW)-scale applications, highlighting its potential as a practical technology for industrial deployment.

"This study demonstrates the large-scale synthesis of low-cost, non-precious metal catalysts and validates their performance in commercially relevant electrolyzer systems for the simultaneous production of hydrogen and chemical feedbacks," said Juchan Yang, principal researcher at Korea Institute of Materials Science.

Professor Ji-Wook Jang of Ulsan National Institute of Science and Technology added, "Technologies that convert bio-derived byproducts such as glycerol into value-added chemicals represent a key strategy for simultaneously advancing carbon neutrality and the hydrogen economy." READ MORE