Assembly of Bimetallic PdAg Nanosheets and Their Enhanced Electrocatalytic Activity toward Ethanol Oxidation

Abstract

The direct ethanol fuel cells in an alkaline medium have a broad vision of applications because of their large energy density, reasonable power density, and environmentally friendly features. Herein, we present a facile one-step method to synthesize PdAg nanosheet assemblies (NSAs) in a mixed solution of N,Ndimethylformamide and water with the addition of molybdenum hexacarbonyl and cetyltrimethylammonium bromide. Pure Pd NSA shows an irregular shape while PdAg NSAs gradually undergo a process from solid assembly to a hollow structure with the Pd/Ag molar ratio changing from 3:1 to 2:1 to 1:1. The formation of alloy nanosheets in the assemblies combined with the introduction of Ag in the Pd catalyst enhances the catalytic activity toward ethanol electrooxidation from 1524 mA mg −1 of pure Pd NSA to 1866 mA mg −1 of PdAg NSA with a Pd/Ag molar ratio of 2:1. On the basis of the experimental data, compared with pure Pd structures, both the nature of a thin nanosheet of PdAg NSAs and the structural changes in the alloy assemblies play key roles in determining the electrocatalytic activity of these Pd-based catalysts.

Synthesis of Free‐Standing Alloyed PdSn Nanoparticles with Enhanced Catalytic Performance for Ethanol Electrooxidation

“…As one of the platinum group metals, the development of palladium (Pd) catalysts has aroused great interest because they exhibit excellent electrocatalytic activities both in anode and in cathode reactions. [18][19][20][21][22][23][24][25][26] Recently, great efforts have been focused on tuning the composition structures of Pd-based catalysts by introducing foreign metals. [13,22] Various morphologies of Pd-based materials have been synthesized with special structures (eg.…”

“…[18][19][20][21][22][23][24][25][26] Recently, great efforts have been focused on tuning the composition structures of Pd-based catalysts by introducing foreign metals. [13,22] Various morphologies of Pd-based materials have been synthesized with special structures (eg. nanowires, nanorods, nanosheets, nanocubes, and nanoparticles).…”

PdAg/C Electrocatalysts Synthesized by Thermal Decomposition of Polymeric Precursors Improve Catalytic Activity for Ethanol Oxidation Reaction

“…For comparison purposes, Table 6 presents a brief summary of results observed in the literature for PdAg catalysts and the Pd 60 Ag 40 /C evaluated in this study. Observing the results presented in Tables 5 and 6, it is possible to conclude that Pd 60 Ag 40 /C produced by the technique of thermal decomposition of polymeric precursors has been shown to be a viable alternative for anodes in fuel cells in EOR [27,29,40,[46][47][48][49], because it requires lower amounts of Pd with good catalytic activities and consequent economy in the cost of the Pd salt.…”

Construction of Concave PdAg Nanoshells with Limited Thickness for Efficient Electroxidation of Ethanol

“…Moreover, the alloying of Pd with other metals and/or modification with non-metal elements could be a feasible strategy to improve the electrochemical performance since it can tune the surface affinity towards key intermediates to achieve the maxima electrocatalytic activity along the volcano-type plot as a function of the heat of adsorption and also enhanced anti-poisoning ability of the electrocatalyst (Zhang et al, 2016b). To this end, the electrochemical activity of many metal combinations, such as PdAu (Feng et al, 2013;Hong et al, 2014;Yang et al, 2017), PdPt (Dutta et al, 2016), PdAg (Lu and Chen, 2012;Peng et al, 2015;Bin et al, 2016;Fang et al, 2018;Lv et al, 2019;Yang et al, 2020a;You et al, 2020;Cui et al, 2021;Nguyen et al, 2021), PdCu (Wang et al, 2012;Hu et al, 2014;Liu et al, 2015;Jiang et al, 2016;Yang et al, 2019;Jana et al, 2021), PdPtCu (Wang et al, 2020), and phosphorousdoped Pd-based nanocrystals (Liu et al, 2019;Yang et al, 2020b;Lv et al, 2020;Yu et al, 2020), have been extensively measured, where the underlying mechanisms are investigated using theoretical deduction (i.e., d-band center theory) and in situ techniques (i.e., in situ FTIR).…”