Enhanced Mass Activity and Stability of Bimetallic Pd‐Ni Nanoparticles on Boron‐Doped Diamond for Direct Ethanol Fuel Cell Applications

Abstract

In this work, electrochemical deposition of Pd and bimetallic Pd−Ni nanoparticles on an oxygen‐terminated boron‐doped diamond (BDD) substrate is described for use as an electrocatalyst in a direct ethanol fuel cell. A potentiostatic two‐step electrochemical method involving the electrodeposition of Ni nanoparticles on BDD followed by mono‐dispersed Pd nanoparticles was used for the fabrication of a Pd−Ni/BDD electrode. The electrocatalytic activity of the bimetallic Pd−Ni nanoparticles was evaluated in an alkaline solution containing ethanol and compared to that of the Pd nanoparticles alone. The bimetallic Pd−Ni nanoparticles showed 2.4 times higher mass activity than similar systems in the literature as well as stability when operated in alkaline media. The higher electrochemical response towards the electrooxidation of ethanol observed for the bimetallic electrocatalysts was attributed to the synergistic effects of the electron interaction at the interface of the two metals. Chronopotentiometric measurements revealed that Pd is more stable when anchored to the Ni nanoparticles. The optimised loading of mono‐dispersed Pd on a foreign Ni metal as nanoparticles plays a crucial role in achieving a high mass (3.63×106 mA/g) and specific (10.53 mA/cm2) electrocatalytic activity of Pd towards ethanol electrooxidation in alkaline media.

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

“…The catalytic current densities of the Pd 20 Sn 24 NP‐modified GCEs in different catalytic temperature and reaction media are shown in Figure 7 and Table S2. It can be concluded that higher values of temperature, pH value, and ethanol concentration should have positive effects on overall reaction especially for the rate determination step on EOR [27,41] …”

“…It can be concluded that higher values of temperature, pH value, and ethanol concentration should have positive effects on overall reaction especially for the rate determination step on EOR. [27,41] Figure 8A shows a series of CV curves of the Pd 20 Sn 24 NPmodified GCE at different cycles. The current density increases gradually and reaches the peak value at the 39 th cycle, corresponding to the activation of Pd atoms and removal of surfactants produced by synthesis reactions, followed by the expose of fresh Pd atoms.…”

Palladium Nanoparticles Supported on B‐Doped Carbon Nanocage as Electrocatalyst toward Ethanol Oxidation Reaction

“…[33] Furthermore, boron is less electronegative than carbon and can act as an electron-withdrawing site when entering carbon lattice. [34,[38][39][40] As support for fuel cell reaction process, hollow borondoped carbon materials had aroused great attention, due to its several superiorities, such as unique hollow architecture, large special surface area and abundant B-doped active site. Accordingly, it has been observed that Bdoped carbonaceous material efficiently improved the Pd-based catalytic performances compared with undoped carbon catalyst support in several catalytic processes.…”

“…Accordingly, it has been observed that Bdoped carbonaceous material efficiently improved the Pd-based catalytic performances compared with undoped carbon catalyst support in several catalytic processes. [34,[38][39][40] As support for fuel cell reaction process, hollow borondoped carbon materials had aroused great attention, due to its several superiorities, such as unique hollow architecture, large special surface area and abundant B-doped active site. Hence, hollow boron-doped carbon architecture can anchor metal nanoparticles, prevent aggregation of metal NPs, and promote electrolyte permeation and charge transmission to improve the catalytic performance.…”

Direct Glycerol Fuel Cells: Comparison with Direct Methanol and Ethanol Fuel Cells

“…[10,11,13] Pt-based catalysts are of better kinetics but suffer from poisoning by CO. [7,11] Pd-based catalyst can catalyze several alcohol electro-oxidation, in alkaline media. [10,11,[18][19][20][21] Arjona et al, [8] studied the use of Pd and Pt electrodeposited on three-dimensional carbon paper and carbon nanofoam for glycerol oxidation in alkaline media. Pt showed good activity for glycerol oxidation, exhibiting more negative potential (the onset potential happened at 130 mV lower) than Pd-based materials.…”