Ultrathin and Wavy PdB Alloy Nanowires with Controlled Surface Defects for Enhanced Ethanol Oxidation Electrocatalysis

Abstract

Engineering crystalline structures/defects and elemental compositions is synthetically critical to optimize surface features of noble metal nanocrystals and thus improve their catalytic performances in various reactions. In this manuscript, we report a facile one-step aqueous synthesis of onedimensional (1D) noble metal−metalloid alloy nanowires (NWs) with an ultrathin and wavy morphology, controlled crystalline defects, and binary PdB compositions as a highly efficient catalyst toward the electrochemical ethanol oxidation reaction (EOR). We show that the utilization of hexadecylpyridinium chloride as functional surfactant is of great importance to confine in-thecolumnar epitaxial nucleation of anisotropic ultrathin PdB NWs, while the attachment growth precisely controls their surface crystalline defects with a wavy morphology. Meanwhile, this strategy is synthetically universal and can be readily extended to engineer an ultrathin wavy morphology and crystalline defect of ternary PdMB (M = Cu and Pt) alloy NWs. Owing to multiple structural and compositional merits, resultant PdB alloy NWs synergistically expose more electrocatalytically active sites and also kinetically accelerate the removal of CO-related poisons, remarkably improving electrocatalytic EOR activity and stability compared to their counterpart catalysts. Besides, wavy PdB alloy NWs are also electrochemically more active for electrocatalytic oxidation of other alcohols (methanol, glycerol, and glucose). The findings reported here thus shed a bright light on rational design of the high-performance metal alloy catalysts for their potential applications in fine chemical synthesis, fuel cells, and beyond.

Boron-Doped Platinum-Group Metals in Electrocatalysis: A Perspective

“…37 In addition, by adding an amphiphilic surfactant template, this aqueous synthesis involving DMAB can be further extended to construct different nanostructured Pd−B alloys such as nanospheres, nanowires, nanopillars, and so on. 52,56,59,60 To increase the B-doping content in Pd−B alloys, Chen at al. 40 used N, N-dimethylformamide (DMF) as the solvent to synthesize Pd−B nanocrystals using NaBH 4 as the reductant and B source.…”

“…Take the synthesis of Pd–B for example; both inorganic borohydride and organic borane compounds were used in aqueous preparations. Among them, dimethyl aminoborane (DMAB) has been extensively used as the B source and reduction agent under alkaline conditions at a low temperature controlled by a ice-water bath. ,− The relevant reactions are given as follows: …”

Cyanogel‐Induced PdCu Alloy with Pd‐Enriched Surface for Formic Acid Oxidation and Oxygen Reduction

“…[21] Apart from component regulation to improve the intrinsic activity, tailoring the desirable morphology to increase the number of active sites of catalysts can achieve another effective approach for advanced electrocatalytic performance. [23][24][25] At present, a variety of Pd-based catalysts with unique morphology have been constructed, including 0D geometric nanoparticles, [26] 1D nanorods and nanowires, [27][28][29][30] 2D nanosheets [9,31] and 3D networked nanostructures. [32][33][34] In particular, the 3D structure often can endow superior electrocatalytic performance of the Pd-based catalysts via maximizing the exposed active area, creating high active sites available, and maintaining extremely suitable nanostructure.…”

Low Pt-Doped Crystalline/Amorphous Heterophase Pd12P3.2 Nanowires as Efficient Catalysts for Methanol Oxidation

“…or nonmetallic elements (B, , P, , etc.). For example, PdB nanowires (NWs) and PdP nanosheets (NSs) have been prepared as anode catalysts for ethanol oxidation reaction (EOR). , Compared to other Pd-based catalysts, palladium phosphides have shown superior electrical conductivities and activities. However, the fabrication of palladium phosphides usually takes place at a relatively high temperature, which limits their wide application. , Besides the formation of bimetallic Pd-based catalysts, the crystal-phase structure is also a key factor in determining the electrochemical catalytic performance.…”

“…For example, PdB nanowires (NWs) and PdP nanosheets (NSs) have been prepared as anode catalysts for ethanol oxidation reaction (EOR). 34,35 Compared to other Pd-based catalysts, palladium phosphides have shown superior electrical conductivities and activities. However, the fabrication of palladium phosphides usually takes place at a relatively high temperature, which limits their wide application.…”