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• Colloidal palladium tin nanoparticles containing phosphorous are produced. • PdSnP/C catalysts show record activity towards the formate oxidation reaction. • DFT calculations show phosphorus promotes FOR through an electronic mechanism. The deployment of direct formate fuel cells (DFFCs) relies on the development of active and stable catalysts for the formate oxidation reaction (FOR). Palladium, providing effective full oxidation of formate to CO 2 , has been widely used as FOR catalyst, but it suffers from low stability, moderate activity, and high cost. Herein, we detail a colloidal synthesis route for the incorporation of P on Pd 2 Sn nanoparticles. These nanoparticles are dispersed on carbon black and the obtained composite is used as electrocatalytic material for the FOR. The Pd 2 Sn 0.8 P-based electrodes present outstanding catalytic activities with record mass current densities up to 10.0 A mg Pd -1, well above those of Pd 1.6 Sn/C reference electrode. These high current densities are further enhanced by increasing the temperature from 25 °C to 40 °C. The Pd 2 Sn 0.8 P electrode also allows for slowing down the rapid current decay that generally happens during operation and can be rapidly re-activated through potential cycling. The excellent catalytic performance obtained is rationalized using density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn–MnO2 batteries are attracting attention as a cost‐effective and safe energy storage solution, but their commercialization faces challenges due to limited stability, output voltage, and energy density. Herein, a hybrid‐ion Zn–MnO2 system with enhanced Mn4+/Mn2+ electrochemical contribution is introduced using an Al3+‐based electrolyte. Compared with conventional Zn2+ electrolytes, the hybrid Al3+/Zn2+ cell offers higher output voltage of 1.75 V, capacities up to 469 mAh g−1, and outstanding energy densities up to ≈730 Wh kg−1 at 0.3 A g−1. Besides, the Al3+‐enabled Zn–MnO2 battery shows 100% capacity and energy density retention after 10,000 cycles at 2 A g−1. Even at a high mass–loading of 6.2 mg cm−2, a capacity of ≈200 mAh g−1 is maintained for over 100 cycles. This outstanding performance is related to the contribution of different intercalation and reaction mechanisms, as proved by the combination of electrochemical analysis and ex‐situ x‐ray diffraction characterization of the cells at different discharge stages. Al3+ ions, as Lewis strong acid, contribute to capacity in two significant ways: through a highly reversible intercalation/de‐intercalation that substantially boosts capacitance at low current rates, and promoting the Mn4+/Mn2+ reaction aided by H+ that dominates the capacitance at higher current rates. Overall, this work demonstrates a practical Zn–MnO2 battery with a high potential for low‐cost stationary energy storage habilitated by multiple ion co‐intercalation. [ABSTRACT FROM AUTHOR]