Ordered PdCu-Based Core–Shell Concave Nanocubes Enclosed by High-Index Facets for Ethanol Electrooxidation

Abstract

Crystal phase engineering is a powerful strategy for regulating the performance of electrocatalysts toward many electrocatalytic reactions. Herein we demonstrate that Au@Pd1Cu concave nanocubes (CNCs) with an ordered body-centered cubic (bcc) PdCu alloy shell enclosed by many high active high-index facets can be adopted as highly active yet stable electrocatalysts for the ethanol oxidation reaction (EOR). These CNCs are more efficient than other nanocrystals with a disordered face-centered cubic (fcc) PdCu alloy surface and display high mass and specific activities of 10.59 A mgpd –1 and 33.24 mA cm–2, which are 11.7 times and 4.1 times higher than those of commercial Pd black, respectively. Our core–shell CNCs also exhibit robust durability with the weakest decay in activity after 250 potential-scanning cycles, as well as outstanding antipoisoning ability. Alloying with Cu and the ordered bcc phase surface can provide abundant OHads species to oxidize carbonaceous poison to avoid catalyst poisoning, and the exposed high-index facets on the surface can act as highly catalytic sites.

Regulation of the shell thickness and shell components in PtCu/PdCu core–shell tripods for ethylene glycol and glycerol oxidation reactions

“…All the above phenomena show a great change in the electronic structure in PtCu/PdCu TDNs, so it can be further indicated that the direction of electron transfer in the core-shell structure is from Cu to Pt to Pd. 34,38,39 Our strategy can also be used to synthesize PtCu/MCu (M ¼ Rh, Ru, Ir, Au) heterostructure TDNs. When Na 3 RhCl 6 was introduced into PtCu TDNs, more small particles were attached around the PtCu TDNs, as seen in Fig.…”

“…All the above phenomena show a great change in the electronic structure in PtCu/PdCu TDNs, so it can be further indicated that the direction of electron transfer in the core–shell structure is from Cu to Pt to Pd. 34,38,39…”

“…31,32 If the noble metal Pd is alloyed with the transition metal Cu as the shell, not only can the dband center of Pd be reduced, but also the introduction of Cu can promote the formation of adsorbed OH (OH ads ) species, which can remove the poisoning intermediates in the alcohol oxidation process. 29,33,34 Although the selective coverage of Cu on the Pd shell surface improves the resistance of the catalyst to CO ads poisoning during alcohol oxidation, the stability of PdCu is mainly dependent on the coordination of Cu atoms on the surface. More Cu atoms would block the active sites on the Pd surface, thus negatively affecting the alcohol oxidation performance, and the leaching of its components would hinder the durability of this catalyst.…”

Tuning the Selective Ethanol Oxidation on Tensile‐Trained Pt(110) Surface by Ir Single Atoms

“…[ 1 ] Among them, direct ethanol fuel cells (DEFCs) have attracted much attention in the field of fuel cells due to the high theoretical energy density, low toxicity, and biomass production of ethanol. [ 2,3 ] Currently, the widespread application of DEFCs is mainly impeded by the sluggish kinetics of 12‐electron complete electro‐oxidation of ethanol to CO 2 . [ 4,5 ] Academia and industry widely accept that ethanol oxidation reaction (EOR) at the anode of DEFCs obeys C1 and C2 dual‐pathway reaction mechanism.…”

“…DOI: 10.1002/smll.202202587 of ethanol. [2,3] Currently, the widespread application of DEFCs is mainly impeded by the sluggish kinetics of 12-electron complete electro-oxidation of ethanol to CO 2 . [4,5] Academia and industry widely accept that ethanol oxidation reaction (EOR) at the anode of DEFCs obeys C1 and C2 dual-pathway reaction mechanism.…”