Strain Engineering of Face-Centered Cubic Pd-Pb Nanosheets Boosts Electrocatalytic Ethanol Oxidation

Strain engineering of nanomaterials provides a promising avenue to tune the physicochemical properties of nanomaterials. Meanwhile, preparing low-dimension nanomaterials like nanosheets in a facile way remains challenging. Herein, we prepared a class of strained 2D palladium-lead nanosheets with face-centered cubic structures. Those nanosheets can expose a lot of active sites for ethanol oxidation reaction (EOR). The strain values of PdPb-CA are calculated to be 0.2, 1.5, and 2.0%, where the corresponding values increase as more lead atoms are doping, followed by decreased binding energies. This means that the strain effect would upshift the d-band center toward the Fermi level, with a consequence in stronger binding ability. Impressively, PdPb-CA-2 possesses 2431 mA mgPd-1 toward EOR, approximately 4.2 times higher than the commercial Pd/C counterpart. Interestingly, PdPb-CA exhibits a volcano-type behavior, where the maximum electrocatalytic activity can be obtained from the equilibrium condition of the adsorption energies of the active intermediate (OH*) and the blocking species (CO*). This work reveals a promising approach to constructing low-dimensional nanocatalysts with abundant active sites and controllable strain degrees as efficient fuel cell catalysts.

Automated summary

Strain engineering is a promising method to tune the properties of nanomaterials, but the preparation of low-dimensional nanomaterials, such as nanosheets, remains challenging. In this study, strained 2D palladium-lead nanosheets with face-centered cubic structures were successfully prepared, which exhibited a high number of active sites for ethanol oxidation reaction. The strain effect was found to enhance the binding ability of the nanosheets, leading to significantly improved electrocatalytic activity. This study provides a promising approach to construct efficient fuel cell catalysts with abundant active sites and controllable strain degrees.