Highly Efficient and Durable Pd Hydride Nanocubes Embedded in 2D Amorphous NiB Nanosheets for Oxygen Reduction Reaction

Abstract

A highly efficient and durable electrocatalyst of Pd hydride nanocubes encapsulated within 2D amorphous Ni‐B nanosheets is reported. The PdH0.43 nanocubes are first synthesized via a simple N,N‐dimethylformamide thermal treatment. The as‐synthesized PdH0.43 nanocubes are then encapsulated in 2D amorphous NiB nanosheets by NaBH4 reduction in the presence of nickel species. During the NaBH4 treatment, the PdH0.43 can be further transformed into PdH0.706 due to the presence of endogenous H2. Electrochemical studies demonstrate that the degree of hydride of Pd nanocubes (PdHx) plays an important role in the enhancement of their oxygen reduction reaction (ORR) activity. With increasing x value, both the activity and stability increase significantly. At 0.90 V versus reversible hydrogen electrode, the ORR activity of PdH0.706 @Ni‐B reaches 1.05 A mgPd−1, which is nearly five times higher than that of the state‐of‐the‐art Pt catalysts. Accelerated durability tests show that even after 10 000 potential cycles, there is negligible shift in their half‐wave potential and no shape and structure change occurs, indicating the incorporation of amorphous 2D Ni‐B nanosheets can greatly improve their stability without compromising their activity. The present study illustrates the importance of high degree of hydride and presence of amorphous Ni‐B nanosheets on the enhancement of ORR activity for Pd‐based electrocatalyst.

Synthesis of PdH0.43 nanocrystals with different surface structures and their catalytic activities towards formic acid electro-oxidation

“…Combining the experimental data and our previous studies, the enhanced catalytic performance could be attributed to the distinct electronic structure of PdH x . The interaction of H with Pd would lead to the downshift of the Pd d-band center [21,[31][32][33][34][35], which weakens the bonding interaction between noble metal atoms and reaction intermediates and thereby lows the onset oxidation potential. We further conducted CO electro-oxidation experiment to check the CO-tolerance property of the three as-prepared PdH 0.43 NCs (Fig.…”

Phase Modulating of Cu–Ni Nanowires Enables Active and Stable Electrocatalysts for the Methanol Oxidation Reaction

“…Abundant strategies have been devoted to preparing a non‐noble metal catalyst with enhanced performance for the MOR. Among them, phase engineering, a newly investigated strategy, has harvested promising catalytic enhancement . The key element of the phase‐engineered strategy is to combine more than one phases into a unit, which provides additional performance enhancement beyond the catalyst with a single phase due to the synergistic effect from different components as well as the diversities in morphology .…”

“…Amongt hem, phase engineering, an ewly investigated strategy,h as harvested promising catalytic enhancement. [13][14][15] The key element of the phase-engineered strategyi st oc ombine more than one phases into au nit, whichp rovides additional performance enhancement beyond the catalystw ithas ingle phase due to the synergistic effect from different components as well as the diversities in morphology. [16][17][18] On the other hand, one-dimensional structures, such as nanowires and nanotubes, show great potentiali ne lectrochemical applications because they own al arge surfacea rea and abundant high-index facets for electrochemical activity,a ne asy electron and mass transport for better conductivity,a sw ell as an excellent prohibition for vulnerability to dissolution.…”

Serpentine Ni3Ge2O5(OH)4 Nanosheets with Tailored Layers and Size for Efficient Oxygen Evolution Reactions

“…Among these catalysts, some transition metals (Ni, Co, Fe, Mn etc. )‐based oxides, hydroxides, sulfides, and borides are considered alternatives to noble metal Ir‐ and Ru‐ based compounds, due to their favorable electrochemical activity, low cost, and natural abundance. Electrocatalytic performance of these compounds varies vastly depending on compositions and microstructures.…”