A nanoporous PdNi (NP-PdNi) alloy with uniform structure dimension is easily fabricated by one-step mild dealloying of a PdNiAl precursor alloy. NP-PdNi consists of an interconnected nanoscaled network backbone and bicontinuous hollow channels in all three dimensions with a typical ligament size of around 5 nm. Electrochemical measurements indicated that the NP-PdNi alloy has superior electrocatalytic activity towards oxygen reduction reaction (ORR) with much higher specific and mass activities as well as higher methanol tolerance compared with Pt/C catalysts. Importantly, NP-PdNi suffers less loss of the ORR activity and the electrochemical surface area of metal upon 5000 potential cycles in acid solution than Pt/C, indicating a better catalytic durability. The NP-PdNi alloy holds great application potential as a cathode electrocatalyst in the fuel cell related technology with unique ORR performance, high structure stability, and easy preparation.

Supported Pd catalysts are active in catalyzing the highly exothermic methane combustion reaction but tend to be deactivated owing to local hyperthermal environments. Herein we report an effective approach to stabilize Pd/SiO2 catalysts with porous Al2O3 overlayers coated by atomic layer deposition (ALD). 27Al magic angle spinning NMR analysis showed that Al2O3 overlayers on Pd particles coated by the ALD method are rich in pentacoordinated Al3+ sites capable of strongly interacting with adjacent surface PdOx phases on supported Pd particles. Consequently, Al2O3‐decorated Pd/SiO2 catalysts exhibit active and stable PdOx and Pd–PdOx structures to efficiently catalyze methane combustion between 200 and 850 °C. These results reveal the unique structural characteristics of Al2O3 overlayers on metal surfaces coated by the ALD method and provide a practical strategy to explore stable and efficient supported Pd catalysts for methane combustion.

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Nanoporous (NP) PdPt alloy with uniform ligament size and controllable bimetallic ratio is easily fabricated through the selective dealloying of Al from PdPtAl ternary alloys. Compared with commercial Pd/C, Pt/C, NP-Pd, and NP-Pt catalysts, the as-prepared NP-PdPt exhibits greatly enhanced electrocatalytic activity for formic acid oxidation. Moreover, NP-PdPt presents superior catalytic durability upon alloying with Pt, with less loss of the formic acid oxidation activity upon long term potential scans. The NP-PdPt alloy holds great potential in applications as a promising anode catalyst in direct formic acid fuel cells.