Trifunctional Rare‐Metal‐Free Electrocatalysts Prepared Entirely from Biomass

As part of ongoing efforts to realize a low‐carbon and hydrogen‐based society, there is an increasing demand for high‐performance electrocatalysts, which are key materials for fuel cells and water electrolysis systems. Although platinum group metals exhibit high catalytic activity, increasing production costs due to resource constraints, limited countries of production, and geopolitical supply issues are threatening their use. Therefore, it is crucial to make substantial changes in resource utilization for the sustainable production of electrochemical catalysts. Herein, the preparation of trifunctional biomass‐derived electrocatalysts for the oxygen reduction reaction and oxygen/hydrogen evolution reactions by the pyrolysis of cellulose nanofibers from ascidian tunicates, dried blood meal, and cyanocobalamin is reported. The combination of N, P, FeN4, and CoN4 structures incorporated in the carbon network leads to high electrochemical performance comparable with rare‐metal‐based electrocatalysts and other carbon alloy electrocatalysts. This work provides a possible strategy for fabricating high‐capacity energy storage devices from biomass resources such as industrial waste without the need for rare metals or other harmful heavy metals. Trifunctional biomass‐derived electrocatalysts for the oxygen reduction reaction and oxygen/hydrogen evolution reactions are prepared by the pyrolysis of cellulose nanofibers from ascidian tunicates, dried blood meal, and cyanocobalamin.