Search

In the domain of stationary high-capacity energy storage, vanadium redox flow batteries (VRFBs) emerge as frontrunners, showcasing remarkable advantages over lithium-ion counterparts in terms of safety, cycle life, and system residual value (resource recycling). Nonetheless, the high manufacturing cost of electrolyte persists as a formidable obstacle to extended commercialization. The utilization of formic acid as a reducing agent for catalyzing the production of vanadium electrolytes presents a promising and economically viable avenue. However, the principal bottleneck hindering large-scale electrolyte production resides in the inadequate activity and durability of catalysts. We have developed the core-shell catalyst featuring the Pd core enveloped by the Pt shell, employed for the production of V3.5+electrolyte via catalytic reduction. Notably, the core-shell catalyst with a Pd/Pt molar ratio of 1:2 displayed a remarkable 2.4-fold increase in activity compared to commercial Pt/C. The incorporation of Pd alters the oxidation pathway of formic acid on Pt/C and relatively weakens the binding with the intermediate of CO, thereby enhancing the resistance against poisoning of the catalyst. Concomitantly, the Pt shell effectively mitigates the deactivation issue of Pd during formic acid oxidation. The core-shell catalyst with a Pd/Pt molar ratio of 1:2 exhibits no metal leaching in the reaction and maintains excellent and stable efficiency in repeated production, proving to be a promising catalyst for the production of high-quality V3.5+electrolyte.