Direct ethylene glycol fuel cells (DEGFCs) necessitate cost-effective and efficient electrocatalyst toward oxidation of ethylene glycol (EG) to overcome the challenges associated with sluggish anodic oxidation reaction kinetics. Herein, Poly(3,4-ethylenedioxythiophene) (PEDOT) granules support well-dispersed Ru-doped Pd electrocatalysts (PdRu/PEDOT) were synthesized. The optimized Pd 4 Ru 2 /PEDOT demonstrates exceptional electrocatalytic performance toward alkaline EG oxidation reaction (EGOR) electrocatalysis, achieving the mass activity of 4141.8 mA mg Pd -1 . The exceptional catalytic activity stems from the three-dimensional porous structure of Pd 4 Ru 2 /PEDOT, which presents abundant active sites and kinetically accelerates electron/reactant transport within its mesoporous architecture. In addition, the results of long-term cyclic voltammetry (CV) and chronoamperometry (CA) tests demonstrate that Pd 4 Ru 2 /PEDOT exhibits superior catalytic durability and anti-poisoning capabilities, attributable to the synergistic effect between the electron-rich conjugated structure of PEDOT and the presence of both Pd and Ru. This study offers novel insights into the development of electrocatalysts for DEGFCs.
Structural information in a disordered atomic system cannot be acquired from everyday X-ray diffractometers, so we have to resort to synchrotron resources. The pair distribution function from synchrotron X-ray and neutron scattering reflects the local bond information regardless of the crystallinity, but the limited access to these high-energy light resources prevents them from widespread use. Here, we develop a microstructure analysis framework to study immiscible binary alloys through the integration of local elemental segregation analysis, electron-based pair distribution function, the corresponding wavelet coherence spectrum, and ab initio level simulation. All the information can be obtained from an in-house transmission electron microscope equipped with an energy-dispersive spectroscope. A series of nanoparticles based on immiscible Pd-Ru alloys are chosen as model catalysts for the hydrogen evolution reaction, and the structure-performance relationship is established on the basis of the electrochemical tests and structural information from the analysis toolkit we developed.
Developing bi-functional electrocatalysts for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) is crucial for enhancing the energy transfer efficiency of metal–air batteries and fuel cells, as well as producing hydrogen with a high purity. Herein, a series of Pd–Ru alloyed nanoparticles encapsulated in porous carbon nanosheets (CNs) were synthesized and employed as a bifunctional electrocatalyst for both ORR and HER. The TEM measurements showed that Pd–Ru nanoparticles, with a size of approximately 1–5 nm, were uniformly dispersed on the carbon nanosheets. The crystal and electronic structures of the PdxRu100−x/CNs series were revealed by powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The as-prepared samples exhibited effective ORR activity in alkaline media and excellent HER activity in both alkaline and acid solutions. The Pd50Ru50/CNs sample displayed the best activity and stability among the series, which is comparable and superior to that of commercial 10% Pd/C. For ORR, the Pd50Ru50/CNs catalyst exhibited an onset potential of 0.903 V vs. RHE (Reversible Hydrogen Electrode) and 11.4% decrease of the current density after 30,000 s of continuous operation in stability test. For HER, the Pd50Ru50/CNs catalyst displayed an overpotential of 37.3 mV and 45.1 mV at 10 mA cm−2in 0.1 M KOH and 0.5 M H2SO4, respectively. The strategy for encapsulating bimetallic alloys within porous carbon materials is promising for fabricating sustainable energy toward electrocatalysts with multiple electrocatalytic activities for energy related applications.Keywords:Pd–Ru alloys;porous carbon nanosheets;bifunctional electrocatalyst;oxygen electroreduction;hydrogen evolution reaction
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