Oxygen Reduction Reaction and Hydrogen Evolution Reaction Catalyzed by Pd–Ru Nanoparticles Encapsulated in Porous Carbon Nanosheets

Abstract

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 Pd x Ru 100−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 Pd 50 Ru 50 /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 Pd 50 Ru 50 /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 Pd 50 Ru 50 /CNs catalyst displayed an overpotential of 37.3 mV and 45.1 mV at 10 mA cm −2 in 0.1 M KOH and 0.5 M H 2 SO 4 , 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.

Tweaking Nickel with Minimal Silver in a Heterogeneous Alloy of Decahedral Geometry to Deliver Platinum‐like Hydrogen Evolution Activity

“…Figure c represents the amount of evolved hydrogen with time and dividing the experimental result by calculated value provides an extremely high efficiency of 99.4 %. The intrinsic figure of merit for HER electrocatalysts, the TOF of AgNi‐5 at 50 mV (versus RHE) is found to be 2.1 H 2 s −1 and at 150 mV (versus RHE) it is 14.6 H 2 s −1 (Supporting Information, Discussion S2), which is at par or larger than the best HER electrocatalysts reported till date (Supporting Information, Table S3) . AgNi‐5 NCs is also found to be remarkably stable both at pH 0 and pH 14 under operational conditions at −0.15 V overpotential for 5 days (Figure d), with no apparent change in its intertwined morphology (Figure d inset).…”

Highly selective etherification of fructose and 5‐hydroxymethylfurfural over a novel Pd‐Ru/MXene catalyst for sustainable liquid fuel production

“…The high intense metallic deconvoluted peaks of Pd 0 3d 5/2 and Pd 0 3d 3/2 are attributed at the binding energies of 336.49 and 341.91 eV, while the less intense oxidized deconvoluted peaks of Pd 2+ 3d 5/2 and Pd 2+ 3d 3/2 are attributed at 331.01 and 342.68 eV, respectively. 44 The deconvoluted Ti 2p spectra in Figure 3H exhibited two main spin-orbit split peaks of Ti p 3/2 and Ti p 1/2 at the binding energies of 457.3 and 462.5 eV, respectively. The deconvoluted peaks of Ti-C (sp 3 ), Ti 2+ , and Ti-O are attributed to the binding energies of 458.13, 460.85, and 463.27 eV, respectively, that are correlated with the chemical state of the MXene.…”

Scalable Carbon Nanotube/Platinum Nanoparticle Composite Inks from Salt Templates for Oxygen Reduction Reaction Electrocatalysis for PEM Fuel Cells

“…Catalyst supports require properties, such as high surface area and high electronic conductivity, to maintain high catalytic activity [13]. While platinum remains an efficient electrocatalyst [14], carbon black degrades over time decreasing durability and increasing the cost of the catalyst due to the need for regeneration [15]. Possible replacements for carbon black are carbon tubule membranes [16], ordered porous carbon [17], graphite nanofibers [18], films of C60 clusters [19], hard carbon spherules [20], and carbon nanotubes [21].…”