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.