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

Abstract

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.

Hybrid water electrolysis with integrated and cascading reactions using two-dimensional electrocatalysts

“…31 Accordingly, using the selected reactions to replace the OER and assemble a hybrid electrolyzer can deliver higher current density with lower voltage input, increasing the energy conversion efficiency. Nowadays, various emerging anodic reactions as OER alternatives have been investigated, including simple compound electrooxidation (i.e., urea oxidation reaction 32,33 and hydrazine oxidation 34,35 ) and complex compound electrooxidation 20 (i.e., ethanol oxidation [36][37][38][39] and HMF oxidation [40][41][42] ) are proven. Theoretically, these reactions generally show lower electrochemical potential than the OER, leading to lower overpotentials for hybrid water splitting and boosting HER performance.…”

“…, urea oxidation reaction 32,33 and hydrazine oxidation 34,35 ) and complex compound electrooxidation 20 ( i.e. , ethanol oxidation 36–39 and HMF oxidation 40–42 ) are proven. Theoretically, these reactions generally show lower electrochemical potential than the OER, leading to lower overpotentials for hybrid water splitting and boosting HER performance.…”