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Direct formic acid fuel cells have attracted significant attention due to their low fuel crossover, high safety, and high theoretical power density among all proton‐exchange membrane fuel cells. Numerous efforts have been dedicated to studying formic acid oxidation, particularly in the fabrication of high‐performance electrocatalysts with economical utilization of Pt metal. In this work, we report a synthetic strategy to create PtAg dots supported on plate‐like Au nanoparticles and explore their applications in electrocatalytic formic acid oxidation. The highly dispersed nature of the catalytic Pt centers and the successful construction of PtAg−Au trimetallic interfaces makes the current nanostructure an ideal system to allow for a synergetic effect between Pt, Au, and Ag, leading to improved electrocatalysis. Compared with commercial Pt/C, our PtAg‐on‐Au heterogenous nanoplates exhibit superior mass activity, along with enhanced reaction kinetics and long‐term durability for FAOR in an acidic medium. Density functional theory (DFT) simulation results indicate that AgPtAu(111) exhibits a relatively high activity for HCOOH oxidation into CO2 among the various Au‐based catalysts. This work provides a viable strategy for constructing Pt‐based electrocatalysts with controlled Pt ensembles, offering insights into the development of fuel cell catalysts that make highly efficient use of costly noble metals. [ABSTRACT FROM AUTHOR]

Morphology control is widely acknowledged as an effective method for optimizing the exposed facets and active sites of palladium (Pd) nanocrystals, which enhances their electrocatalytic activity. However, conventional approaches inevitably alter the reaction from both thermodynamic and kinetic perspectives, rendering control intricate. In this investigation, we introduce a specialized strategy to achieve morphology control over PdAuAg nanocrystals, demonstrating their exceptional performance as electrocatalysts for the ethanol oxidation reaction (EOR). Specifically, three metallic precursor solutions were individually introduced into a one-pot reaction system at controlled rates using syringe pumps, allowing for separate manipulation of each metal atom's concentration without cross-reaction. Consequently, a variety of products with unique morphologies and structures were produced, all adhering to the same protocol except for the rate of metal atom introduction. When catalyzing the EOR, the optimized PdAuAg nanocrystals supported on carbon black exhibited a sevenfold increase in mass activity compared to Pt/C, as well as enhanced reaction kinetics and long-term stability. Density functional theory (DFT) calculations confirmed that crystal facets can influence the ethanol oxidation reaction pathway, rationalizing the improved catalytic performance. Our study presents a viable approach for modulating the morphology of trimetallic nanocrystals by varying the feed rate of metal atoms in a one-pot reduction, illuminating the rational design of high-performance fuel cell catalysts. [ABSTRACT FROM AUTHOR]

The inner pressure that increases due to the complex physical and chemical reactions of batteries plays an important role in thermal runaway early warning and gas injection. However, most of the current thermal-pressure coupling models for batteries cannot accurately describe the gas generation sources and predict the inner pressure increases of multiple jelly rolls. In this work, we propose a thermal-pressure coupling model by combining the gas composition data and the fitting data from the accelerating rate calorimeter experiment. The electrolyte vapor pressure and internal gas composition are obtained under uniform heating conditions. The internal pressure growth source relies on the variation in the gas composition at different temperature ranges to infer. The reaction kinetics equations are then combined with gas generation sources, energy conservation equations and venting process to form a thermal-pressure model, which adopts a distributed structure to adapt to the temperature gradient between jelly rolls. The simulation results indicate that the model can accurately match the reaction gas accumulation phase before the valve venting, as well as the thermal runaway and cooling process temperature after the ejection. The simulation results indicate that when the pressure threshold increases from 0.5 MPa to 0.75 MPa, both the time-to-venting and time-to-peak temperature increase, but the interval between them decreases. Additionally, the explosion concentration range of the mixture gas also increases accordingly. This model revealed the inner pressure increase and thermal runaway process in large-format lithium iron phosphate batteries, offering guidance for early warning and safety design. [Display omitted] • The inner pressure and gas components of the large-format battery are obtained from the ARC test. • A distributed thermal-gas coupling model for large-format battery is established. • Gas generation from evaporation and reaction is included based on ARC test. • The influence of pressure threshold on gas composition and thermal runaway is discussed. [ABSTRACT FROM AUTHOR]