A Class of (Pd–Ni–P) Electrocatalysts for the Ethanol Oxidation Reaction in Alkaline Media

Abstract

A class of Pd−Ni−P electrocatalysts are prepared for the ethanol electrooxidation reaction (EOR). Xray diffraction and transmission electron microscope reveal that the synthesized Pd−Ni−P catalyst possesses a more amorphous structure with smaller particle sizes when compared with a Pd−Ni sample without P and a control Pd black (Pd-blk) sample. The Pd−Ni−P catalyst contains double the number of electrocatalytically active sites (12.03%) compared with the Pd−Ni (6.04%) and Pd-blk (5.12%) samples. For the EOR, the Pd−Ni−P catalyst has the lowest onset potential (−0.88 V vs SCE), the most negative peak potential (−0.27 V vs SCE), and the highest EOR activity in 0.1 M KOH solution. Moreover, a 110 mV decrease in overpotential is observed for the EOR on the Pd−Ni−P catalyst compared with the Pd-blk catalyst. A Tafel slope of 60 mV/dec at low polarization potentials (<−0.76 V vs SCE) was obtained for EOR at a Pd−Ni−P-coated electrode with a reaction rate constant of 2.8 × 10 −4 cm•S −1 •M −1 at −0.3 V vs SCE in KOH media. Finally, we find that the electrooxidation of ethanol on the Pd−Ni−P catalyst undergoes a 4-electron process to acetate.

Improved ethanol electrooxidation performance by shortening Pd–Ni active site distance in Pd–Ni–P nanocatalysts

“…2c (Pd 40 Ni 43 P 17 , 5.3±0.5 nm). Different from the reported phosphides using NaH 2 PO 2 and NaBH 4 /N 2 H 4 as precursors26273233, these as-prepared NPs are very small with rich and adjacent Ni and Pd active sites. From the high-resolution TEM (HRTEM) image, it is clear that the NPs are Pd/Ni–P heterodimers when the phosphorization (at 260 °C) time is only 5 min (Fig.…”

“…By fabricating Pd– M –P ternary phosphide nanoparticles (NPs)262728, the stability and activity of the catalysts can be remarkably improved. The introduction of oxophilic metals such as Ni (Ru, Rh, Sn or Ag) facilitates the formation of OH radicals and drives the EOR without the production of poisoning by-products such as CO426.…”

Facile synthesis of Pd nanoparticles on nano carbon supports and their application as an electrocatalyst for oxidation of ethanol in alkaline media: The effect of support

“…According to results a reaction order about 0.5 was obtained, which was independent of the potential [73,74]. The effect of NaOH concentration on the anodic peak current density related to the electrooxidation of ethanol in the forward scan at the PdNPs/SWCNT/CCE electrocatalyst has been investigated by CV.…”

Recent Advances on Electro-Oxidation of Ethanol on Pt- and Pd-Based Catalysts: From Reaction Mechanisms to Catalytic Materials

“…The use of a mixed carbon-CeO2 support extends the stability of the Pd catalyst under working conditions by promoting ethanol electro-oxidation at lower anode potentials. Nonmetal component can also play a role in the rational design of catalysts [129][130][131][132]. Recently, our group discovered that Pd-Ni-P/C ternary nanocatalysts showed a remarkable enhancement towards EOR compared to Pd-Ni/C, Pd-P/C and Pd/C [117].…”