Zinc–air batteries have attracted interest as an energy-storage technology because of their high energy potential, safety and use of relatively abundant materials. Their development, however, remains closely tied to the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air electrode. Finding non-precious catalysts that can efficiently promote both reactions remains an important challenge.
In a study published in the Journal of Bioresources and Bioproducts , researchers developed a cobalt-based catalyst supported on biomass-derived carbon, focusing on an aspect that is often overlooked in single-atom catalyst design: the curvature of the carbon support. The catalyst, designated CoNPs+SA@NC, contains Co-N 4 single-atom sites and cobalt nanoparticles distributed on curved nitrogen-doped carbon.
The structure was produced using a Zn volatilization-induced pyrolysis strategy. Chinese fir-derived carbon was used as the biomass carbon precursor, while a ZIF-L-based cobalt precursor supplied the metal sites. During high-temperature treatment, the volatilization of zinc disrupted the carbon framework, generating curved and defective carbon domains. At the same time, the biomass-derived structure helped restrict cobalt aggregation, allowing cobalt nanoparticles to form close to Co-N 4 sites.
The researchers found that this spatial arrangement affected the electronic properties of the Co-N 4 sites. Carbon curvature introduced lattice distortion and asymmetric charge redistribution, strengthening metal–support interactions. The resulting electronic reconstruction narrowed the HOMO-LUMO gap and facilitated electron transfer. Nearby cobalt nanoparticles provided an additional electronic influence, helping regulate the adsorption of oxygen-containing intermediates during catalysis.
Electrochemical testing showed that the catalyst achieved a half-wave potential of 0.87 V for ORR and required an overpotential of 290 mV to reach 10 mA cm -2 for OER. The catalyst also maintained 90.1% of its initial ORR current after eight hours of continuous testing, while accelerated durability testing resulted in only a 10 mV decrease after 10,000 cycles.
The catalyst was subsequently evaluated in zinc-air batteries. A liquid-electrolyte battery reached a peak power density of 172 mW cm -2 , while the quasi-solid-state configuration achieved 71 mW cm -2 and remained stable for more than 86 hours. The liquid battery operated for more than 400 hours, indicating that the catalyst architecture could support long-term bifunctional oxygen electrocatalysis.
The study suggests that biomass-derived carbon can provide more than a conductive support for active metal sites. Its mesoscale structure can also be deliberately engineered to modify metal–support interactions and catalytic behavior, offering another route for developing non-precious bifunctional catalysts for zinc-air batteries.
See the article:
DOI
https://doi.org/10.1016/j.jobab.2026.100297
Original Source URL
https://www.sciencedirect.com/science/article/pii/S2369969826000691
Journal
Journal of Bioresources and Bioproducts
Experimental study
Not applicable
Curvature-Induced Metal-Support Interaction Regulates Co-N4 Electronic Structure for Enhanced Oxygen Electrocatalysis
25-Aug-2026