Search

Highly active Pt‐based intermetallic nanoparticles (i‐NPs) loaded on stable supports have garnered considerable interest as promising oxygen reduction reaction (ORR) catalysts for proton‐exchange‐membrane fuel cells (PEMFCs). Herein, thermostable tellurium (Te) is vapor‐deposited onto commercial conductive carbon to anchor high‐temperature‐synthesized Pt3Co i‐NPs. Advanced characterization and density functional theory (DFT) calculations demonstrate that the binding energy of Pt 4f and Co 2p shift positively by 0.12 and 0.95 eV after the introduction of Te in carbon support, promoting the formation of Pt─Te bonds, which enhances the metal–support interactions (MSIs) in Pt3Co/Te‐C (with a more negative binding energy of −10.28 eV). The average size of well‐dispersed Pt3Co i‐NPs (≈3.9 nm) on Te─C is considerably smaller than that of Pt3Co i‐NPs (≈9.1 nm) on commercial carbon. The specific activity of Pt3Co/Te‐C decreases by only 1.5% after 100,000 ultra‐long voltage‐accelerated cycles, while the morphology remains almost unchanged. The membrane electrode assembly using Pt3Co/Te‐C as a cathode demonstrates impressive activity (power density of 2.32 W cm−2@4 A cm−2 and mass activity of 0.50 A mgPt−1@0.9 V) and robust durability (mass activity@0.9 V loss of 26% after 30,000 cycles with intact L12 ordered structure) in H2–O2 operation, significantly exceeding the DOE 2025 requirements. [ABSTRACT FROM AUTHOR]

Low Pt utilization and intense carbon corrosion of cathode catalysts is a crucial issue for high‐efficiency proton exchange membrane fuel cells due to the highly demanded long‐term durability and less acquisition/application cost. Herein, structurally tunable graphitized mesoporous carbon (GMC) is obtained by direct high‐temperature pyrolysis and in situ‐controlled mesopore formation; the structure‐optimized GMC1300‐1800 exhibits a mesopore size of 7.54 nm and enhanced corrosion resistance. Functionalized GMC1300‐1800 is loaded with small‐sized Pt nanoparticles (NPs) (1.5 nm) uniformly by impregnation method to obtain Pt/GMC1300‐1800 and form an "internal platinum structure" to avoid sulfonic acid groups poisoning as well as ensure O2/proton accessibility. Hence, the electrochemically active surface area (ECSA) of Pt/GMC1300‐1800 reaches 106.1 m2 g−1Pt, while mass activity and specific activity at 0.9 V are 2.1 and 1.4 times those of commercial Pt/C, respectively. Notably, the ECSA decay is less than 17% for both 30 000 cycles' accelerated durability tests (ADTs) of Pt attenuation and carbon attenuation. Accordingly, the optimized mesoporous structure of GMC1300‐1800 significantly decreases the coverage of sulfonic acid groups on Pt NPs, leading to the highest peak power density in the single‐cell test. Density functional theory calculations demonstrate the synergistic effect between graphitization and mesoporosity on enhancing the accessibility and durability of the catalysts. [ABSTRACT FROM AUTHOR]

Atomically distributed transition metal coordinated with nitrogen is considered as a class of promising oxygen reduction reaction (ORR) catalyst. However, the challenge of ineffective distribution of Fe‐Nx active sites have been long existing, leading to low active site density and unstable performance, which needs be overcome for next generation ORR electrocatalysts. Herein, yttrium (Y) is introduced into atomically dispersed iron (Fe) nitrogen co‐doped carbon materials to integrate nanoparticles, nanoclusters, and atomic sites, which endow the Fe‐N4‐Y2O3 and Fe4N0.94‐Y2O3 (FeY‐NC) with outstanding ORR activity. The FeY‐NC achieves half‐wave potential of 0.926 and 0.809 V in alkaline and acidic condition, respectively. The kinetics current density at 0.9 V in alkaline condition is 31.2 mA cm−2, which is 7.8 times of Fe‐NC and 32.4 times of Pt/C. This outstanding activity of FeY‐NC is enabled by the generated atomic FeN4 and Fe4N nanoparticles dual active‐sites, and further the synergistic effect between the Fe‐Nx/Fe4N0.94 with Y2O3 nanoclusters are loaded on nitrogen‐doped carbon (NC) network. The superior performance of FeY‐NC is demonstrated in a primary Zinc‐air battery, deliver a peak power density of 233 mW cm−2. [ABSTRACT FROM AUTHOR]