Researchers have created a catalyst from lignin, a byproduct of paper production, that enhances clean hydrogen generation through water electrolysis. The material demonstrates low overpotential and high stability, offering a sustainable alternative to costly precious metals. This advancement could make large-scale hydrogen production more economical and environmentally friendly.
Scientists at institutions including Guangdong University of Technology have transformed lignin, an abundant waste from paper and biorefinery industries, into a high-performance catalyst for hydrogen production. By embedding nickel oxide and iron oxide nanoparticles into carbon fibers derived from lignin, the team developed a structure that excels in the oxygen evolution reaction, a key step in water electrolysis.
The process involves electrospinning and thermal treatment to convert lignin into nitrogen-doped carbon fibers, which provide conductivity, high surface area, and stability. These fibers support the metal oxides, forming a nanoscale heterojunction that facilitates efficient binding and release of intermediate molecules. This design prevents particle agglomeration, a common problem in base metal catalysts, and enhances electron transport.
Testing revealed the catalyst, termed NiO/Fe3O4@LCFs, achieves an overpotential of 250 mV at 10 mA cm² and maintains stability for over 50 hours at high current densities. It outperforms single-metal catalysts, with a Tafel slope of 138 mV per decade indicating rapid kinetics. In situ Raman spectroscopy and density functional theory calculations confirmed the interface's role in driving the reaction.
"Oxygen evolution is one of the biggest barriers to efficient hydrogen production," said Yanlin Qin, the corresponding author. "Our work shows that a catalyst made from lignin... can deliver high activity and exceptional durability."
The approach leverages globally abundant lignin, avoiding the need for rare metals. "Our goal was to develop a catalyst that not only performs well but is scalable and rooted in sustainable materials," added co-author Xueqing Qiu. This could extend to other metal combinations and reactions, supporting broader clean energy goals. The findings appear in Biochar X on 27 November 2025.