Replicating the Defect Structures on Ultrathin Rh Nanowires with Pt to Achieve Superior Electrocatalytic Activity toward Ethanol Oxidation

Abstract

Metal nanostructures with an ultrathin Pt skin and abundant surface defects are attractive for electrocatalytic applications owing to the increased utilization efficiency of Pt atoms and the presence of highly reactive sites. This paper reports a conformal, layer-by-layer deposition of Pt atoms on defective Rh nanowires for the faithful replication of surface defects (i.e., grain boundaries) on the Rh nanowires. The thickness of the Pt shell can be controlled from one monolayer up to 5.3 atomic layers. This series of Rh@Pt nL (n = 1-5.3) core-sheath nanowires show greatly enhanced activity and durability in catalyzing the ethanol oxidation reaction in an acidic medium. Among others, the Rh @ Pt 3.5L nanowires show the greatest mass activity (809 mA mg −1 Pt ) and specific activity (1.18 mA cm −2 ) after loaded on carbon support, which are 3.7 and 3.4 times those of the commercial Pt/C, respectively. In situ Fourier transform infrared spectroscopy studies indicate an enhanced interaction between the outermost Pt layer and the Rh nanowire can promote CC bond cleavage for complete oxidation of ethanol to CO 2 while depress the dehydrogenation of ethanol to acetic acid. As the Pt shell thickness is increased, the selectivity for the CO 2 pathway decreases while that for acetic acid is increased.

Single‐Atom In‐Doped Subnanometer Pt Nanowires for Simultaneous Hydrogen Generation and Biomass Upgrading

“…Among various alcohols, ethanol, which has high energy density, low toxicity, and valuable upgraded byproducts, has attracted significant attention. [8][9][10] However, upgrading ethanol in traditional industrial settings requires harsh conditions such as high temperature and pressure. As a safe and efficient technique, the ethanol electrooxidation reaction (EOR) has received increasing attention.…”

Ultrasmall Pd‐Cu‐Pt Trimetallic Twin Icosahedrons Boost the Electrocatalytic Performance of Glycerol Oxidation at the Operating Temperature of Fuel Cells

“…More significantly, the NSA would not only bind reactants more weakly but also dissociate reactants more readily than corresponding pure metals . Simultaneously, the surface unsaturated atoms (such as step, edge, and corner) are beneficial to activating the glycerol molecule . Besides, the presence of surface copper atoms can help water dissociate/activate to produce more reactive oxygen species (*OH) (i.e., Cu‐O + H 2 O + 2e‐ ↔ Cu + 2OH − ; Cu + OH − → Cu‐OH ads + e − ), thus enhancing the electrocatalytic performance by oxophilic effect and synergistic effect .…”

Atomic Thickness Catalysts: Synthesis and Applications

“…A recent study showed a layer-by-layer Pt atoms formed on the surface of Rh NWs (Rh@Pt nL ) and the thickness of Pt shell could be controlled in a range of one monolayer to 5.3 atomic layers. [120] It was revealed that the Rh@Pt 3.5L NWs owing the best EOR performance with the highest mass activity and specific activity among all the measured electrocatalysts. In general, three different products are involved on the Pt catalysts in the process of EOR, that are acetaldehyde (CH 3 CHO), acetic acid (CH 3 COOH), and CO 2 by releasing 2, 4, and 12 electrons, respectively.…”

“…Wet-chemical synthesis Noble-metals (alloys), Rh, [53] Pd, [24] Rh@Pt nL , [120] Pd-Pt-Ag, [22] PdMo, [18] PtPdNi, [59] RuCu, [56] AL-Pt@Pt 3 Ga, [21] PtGa [25] ORR, [18,25,59] OER, [9] CRR, [24] MOR, [21,53] EOR [22,120] HER [92] Metallic TMDs, 1T′-MoS 2 [92] LDHs, NiFe-LDHs [9] Hydro/solvothermal synthesis Metal (alloys) Rh, [46] RhPd-H, [3] NiCo, [64] NiMo [65] HER, [3,48,51,65] OER, [8,51] CRR [11] TMOs, MnO 2 , [51] TiO 2 , [48] Ni(OH) 2 [8] Other ATCs: Bi 3 O 4 Br [11] Template-assisted synthesis Various kinds of ATCs, Bi, [91] Fe, [69] Au, [70] PdCo, [80] Sn confined in graphene, [31] 1T-MoS 2 /NiS 2 , [20] hexagonal-MoO 3 [73] ORR, [80] CRR, [91] HER [20] Electrochemistry-assisted synthesis Monolayer metal layer: Pt AL @...…”

“…[21,57,118,119] to Pt to improve the CO tolerance through bifunctional mechanism. [57,120] Briefly, the active sites of the Pt surface will be initially poisoned by the CO ads released by the fuel molecules. Simultaneously, the formation of adsorbed hydroxyl species (OH ads ) will be facilitated by the oxophilic metal at a lower potential to promote the oxidation and eliminating the CO ads .…”