This study reports the preparation, characterization, and electrocatalytic properties of palladium-based catalysts containing ceria (CeO 2 ) on carbon black (CB) and onion-like carbon (OLC) supports. The electrocatalysts (Pd− CeO 2 /CB and Pd−CeO 2 /OLC) exhibit a large specific surface area, pore volume, and small particle size, as well as enhanced interfacial interaction and synergy among Pd, CeO 2 , and OLC in Pd−CeO 2 /OLC that are valuable for improved electrocatalysis. The presence of CeO 2 in Pd−CeO 2 /OLC induces ca. 7% defects and modifies the electronic structure of the Pd/OLC interface, significantly improving the electrical conductivity due to enhanced charge redistribution, corroborated by density functional theory (DFT) calculations. Pd−CeO 2 /OLC displays the lowest adsorption energies (H*, OH*, and OOH*) among the series. For the hydrogen oxidation reaction (HOR), Pd−CeO 2 /OLC delivers significantly enhanced HOR (mass-specific) activities of 4.2 (8.1), 13.2 (29.6), and 15 (78.5) times more than Pd−CeO 2 /CB, Pd/OLC, and Pd/CB, respectively, with the best diffusion coefficient (D) and heterogeneous rate constant (k). Pd−CeO 2 /OLC also displays less degradation during accelerated durability testing. In an anion-exchange-membrane fuel cell (AEMFC) with H 2 fuel, Pd−CeO 2 /OLC achieved the highest peak power density of 1.0 W cm −2 at 3.0 A cm −2 as compared to Pd−CeO 2 /CB (0.9 W cm −2 at 2.2 A cm −2 ), Pd/OLC (0.6 W cm −2 at 1.7 A cm −2 ), and Pd/CB (0.05 W cm −2 at 0.1 A cm −2 ). These results indicate that Pd−CeO 2 /OLC promises to serve as a high-performing and durable anode material for AEMFCs.

A nanostructured Pd/SnO2 on metal‐organic‐framework‐derived carbon (Pd/SnO2/MOFDC) electrocatalyst and its monometallic catalyst (Pd/MOFDC) have been synthesized by microwave‐assisted strategies and investigated for the alkaline hydrogen oxidation reaction (HOR). Physical properties of the electrocatalysts are examined using X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, Brunauer‐Emmett‐Teller analysis, transmission electron microscopy, and density functional theory. This study reveals that the Pd/SnO2/MOFDC possesses superior alkaline HOR activities (in terms of kinetic current, heterogeneous rate constant, diffusivity, exchange current density, and the mass activity) compared to those of the Pd/MOFDC and that are comparable to commercial Pt/C. The improved alkaline HOR activity on Pd/SnO2/MOFDC is attributed to the facile interfacial electrochemical processes arising from the multifunctional properties of SnO2 with the thin Sn film: i) weakening of Pd‐Hads, confirmed by DFT simulation, and ii) oxophilic (thin Sn film) and spill‐over (SnO2) effects that quickly transfer OH− ions to the desorbed Hads for facile reaction in the Volmer rate‐determining step (RDS). Tafel slope (ba=52–102 mV dec−1) and activation energy (EA) values suggest the predominance of the Heyrovsky‐Volmer process. In addition to the improved HOR activity of Pd/SnO2/MOFDC, it also exhibits better stability than Pd/MOFDC. The good performance of Pd/SnO2/MOFDC toward the alkaline HOR promises potential development of low‐cost anode materials for alkaline membrane fuel cells.

Metal-organic framework derived carbon (MOFDC) serves as supporting platforms for PdNi catalyst (Pd/Ni/MOFDC) and acid-treated nickel counterpart (Pd/AT-Ni/MOFDC). The two Pd-based electrocatalysts are tested for alkaline water-splitting (i. e., hydrogen evolution (HER) and oxygen evolution reactions (OER)). The results reveal better HER and OER kinetics for Pd/Ni/MOFDC than Pd/AT-Ni/MOFDC. DFT calculations show that the high performance of the Pd/Ni/MOFDC can be associated with its high conductivity toward adsorbed OH compared to the Pd/AT-Ni/ MOFDC counterpart. The superior overall water-splitting of Pd/Ni/MOFDC describes the synergy between Ni/Ni (OH) 2 interface and nanostructured Pd for possible future application in an electrolyzer.

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