Chloroplasts-derived Ni-based electrocatalyst for efficient electrochemical ethanol oxidation to acetate with hydrogen cogeneration

• Ni-based electrocatalyst was synthesized from chlorophyll extracted from grape leaf waste. • The catalyst achieves 86 % Faradaic efficiency for ethanol-to-acetate conversion at 1.5 V. • Simultaneous hydrogen production at the cathode reaches ∼100 % efficiency. • The bio-derived porous carbon matrix enhances Ni dispersion and charge transfer. • Dual-functional system provides a sustainable and cost-effective alternative to OER. The electrochemical oxidation of biomass-derived organic molecules offers a dual advantage in hydrogen electrolysis: (i) it replaces the sluggish oxygen evolution reaction, accelerating hydrogen generation, reducing cell voltage, and enhancing energy efficiency, and (ii) it valorizes carbon-neutral organic resources into higher-value chemicals. However, the commercial adoption of this strategy relies on the development of electrocatalysts that are cost-effective, energy-efficient, selective, and stable. In this context, biomass not only provides the reactant but also serves as an exceptional resource for creating highly porous and active carbon-based electrocatalysts. In this work, we present a Ni-based electrocatalyst derived from biomass waste, specifically using natural chlorophyll extracted from discarded grape leaves. This catalyst achieves an impressive 86 % Faradaic efficiency for the ethanol oxidation reaction to acetate at 1.5 V, attributed to its large surface area and excellent charge transfer properties. Moreover, it enables 100 % hydrogen production as a co-product at 1.5 V during ethanol oxidation, enhancing its value for energy applications. This study highlights the transformative role of integrating renewable biomass into catalytic systems, demonstrating the potential of biomass-derived materials to drive innovation in electrocatalysis. By converting waste biomass into functional catalysts, this approach advances energy-efficient technologies and addresses environmental challenges of conventional synthesis.