Extraordinary p–d Hybridization Interaction in Heterostructural Pd‐PdSe Nanosheets Boosts C−C Bond Cleavage of Ethylene Glycol Electrooxidation

Abstract

Advanced electrocatalysts for complete oxidation of ethylene glycol (EG) in direct EG fuel cells are strongly desired owing to the higher energy efficiency. Herein, Pd-PdSe heterostructural nanosheets (Pd-PdSe HNSs) have been successfully fabricated via a one-step approach. These Pd-PdSe HNSs feature unique electronic and geometrical structures, in which unconventional p-d hybridization interactions and tensile strain effect co-exist. Compared with commercial Pd/C and Pd NSs catalysts, Pd-PdSe HNSs display 5.5 (6.6) and 2.5 (2.6) fold enhancement of specific (mass) activity for the EG oxidation reaction (EGOR). Especially, the optimum C1 pathway selectivity of Pd-PdSe HNSs reaches 44.3 %, illustrating the superior CÀ C bond cleavage ability. Electrochemical in situ FTIR spectroscopy and theoretical calculations demonstrate that the extraordinary p-d hybridization interaction and tensile strain effect could effectively reduce the activation energy of CÀ C bond breaking and accelerate CO* oxidation, boosting the complete oxidation of EG and improving the catalytic performance.

Atomically Reconstructed Palladium Metallene by Intercalation-Induced Lattice Expansion and Amorphization for Highly Efficient Electrocatalysis

“…Accordingly, the partial density of states (PDOS) were calculated to prove the presence of a p–d interaction. Figure e,f demonstrate that the energy of the Pd-4d band matched well with that of the N-1p band relative to that of the C-1p band, proving a strong p–d orbital hybridization between N and Pd. , The p–d hybridization interaction could result in the redistribution of electrons and thus weakened adsorption of CO on the PdN 0.29 (111) surface to mitigate the poisoning of the catalyst . In addition, the insertion of H, N, and C would induce the charge transfer and electron-deficient Pd due to the half-filled 1s orbital of H and the electronegativity difference between Pd and N/C.…”

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

“…Figure displays the long-term CA curves of the PdPb-CA NSs held at −0.1 V. The “volcano-type” behavior can be observed in CA curves. , It is clear that the PdPb-CA NSs are always the highest and much higher than other samples of the nanosheets. A certain degree of tensile strain would promote EOR but highly strained nanostructures would strengthen the CO* binding with a consequence in decreased mass activity . Impressively, the PdPb-CA-2 NS can maintain 1026 mA mg Pd –1 after 1000 s, further indicating that PdPb-CA-2 NS possesses a greatly increased electrocatalytic mass activity and stability …”

“…A certain degree of tensile strain would promote EOR but highly strained nanostructures would strengthen the CO* binding with a consequence in decreased mass activity. 21 Impressively, the PdPb-CA-2 NS can maintain 1026 mA mg Pd −1 after 1000 s, further indicating that PdPb-CA-2 NS possesses a greatly increased electrocatalytic mass activity and stability. 51…”

“…Therefore, significant efforts have been devoted to designing state-of-the-art catalysts for the oxidation of ethanol. − Instead of pure metals, alloying Pt or Pd with other metals (Fe, Co, Ni, Cu, Ag, Pb, Bi, etc.) to obtain binary/ternary/high-entropy alloys can not only reduce the usage of precious metals but also change the electron structures of the surface or regulate the lattice strain of crystalline Pt-based or Pd-based catalysts, with the consequence being a change of electrocatalytic activity. − In addition, the construction of small-scale Pt-based or Pd-based alloy nanostructured catalysts, especially with one-dimensional (1D) and two-dimensional (2D) nanostructures, can provide a good structural basis for enhancing the electrocatalytic activity of surfaces and interfaces. Not only with abundant surface areas, high conductivity and flexibility as well as inherent anisotropic morphology can be found in this kind of nanomaterial.…”

Synthesis of unconventional Pd–Se nanoparticles for phase-dependent ethanol electrooxidation

“…In all studies attempting to combine non-metal elements with Pd, palladium selenides arouse great interest and show impressive potential in electrocatalysis. 9 In brief, Pd can form a number of stable alloys with selenium (Se) under ambient conditions, e.g. Pd 8 Se, Pd 4 Se, Pd 7 Se 2 , Pd 3 Se, Pd 7 Se 4 , Pd 17 Se 15 , and PdSe 2 .…”