Pt–Ni Octahedra as Electrocatalysts for the Ethanol Electro-Oxidation Reaction

Abstract

Alloying Pt electrocatalysts with late transition metals (e.g., Ni, Co, and Fe) is an effective strategy to lower the catalyst cost and improve their tolerance toward CO in the anode of direct ethanol fuel cells. In this study, shape-controlled octahedral Pt–Ni/C nanocrystals with uniformly exposed (111) facets and an average edge length of 10 nm were synthesized. The octahedral Pt–Ni/C nanocatalyst was at least 4.6 and 7.7 times more active than conventional Pt–Ni/C and commercial Pt/C catalysts, respectively. In situ infrared spectroscopic results showed that the acetic acid/CO2 absorbance peak intensity on octahedral Pt–Ni/C was 7.6 and 1.4 times higher as compared to commercial Pt/C and conventional Pt–Ni/C, respectively, at 0.75 V. This result suggests that ethanol oxidation on octahedral Pt–Ni produces more acetic acid than on other surfaces. The synergistic electronic and facet effects may explain the superior ethanol oxidation reaction activity of octahedral Pt–Ni/C. Further surface modification with Ru significantly lowered the onset potential for CO2 production by ∼100 mV and resulted in a higher selectivity on CO2 as compared to unmodified surface, which further boosted the ethanol utilization efficiency.

Biomass‐Derived 3D Carbon Aerogel with Carbon Shell‐Confined Binary Metallic Nanoparticles in CNTs as an Efficient Electrocatalyst for Microfluidic Direct Ethylene Glycol Fuel Cells

“…The metal contents in the prepared samples were evaluated via the ICP-MS and the values are provided in Table S1 of the Supporting Information. [10,11] However, the high concentration of Ni causes excessive OH ads , leading to inadequate accessibility to the EG molecules. It is noteworthy that the addition of Ni into the Pd lattice increases the resistance towards CO poisoning, which consequently improves the catalytic activity for EG oxidation.…”

“…[34] The durability performances of constructed µDEGFCs were evaluated at a constant potential of 0.35 V for 60 h at room temperature (Figure 7c). [10,11] Furthermore, the existence of graphitic shell over the Pd-Ni nanoparticles provides a competent barrier to avoiding the metal dissolution and aggregation of Pd-Ni under alkaline environment, affirming the superior durability of µDEGFC with Pd 52 -Ni 48 In contrast, a decay of 46.14% and 81.83% in current density, respectively, are observed for Pd 100 /NSCNT/CA(ac)Pt/C/ CP and Pt/C/CP(ac)Pt/C/CP under identical conditions.…”

“…[7] However, Pd nanocatalysts are prone to rapid deterioration under surface poisoning and instability. [10,11] In parallel, metal nanoparticles decorated on carbon supports have also been shown to improve EG oxidation via their high electrical conductivity and catalytic activity. is an efficient strategy to improve the stability without sacrificing the catalytic activity.…”

Catalytic Surface Specificity of Ni(OH)2‐Decorated Pt Nanocubes for the Hydrogen Evolution Reaction in an Alkaline Electrolyte

“…The Tafel slopes for the electrocatalysts were obtained to investigate the RDS of the alkaline HER. [46] However, the role of metallic Ni can hardly be specified in this work owing to its similar water splitting catalytic behaviort oN i(OH) 2 .I nt he case of PN-3/C, however, the larger surface coverage of the Ni(OH) 2 on the Pt surfaces than that of PN-2/C relatively reduces the Pt sites for H ad ,r esulting in the decreased HERk inetics. [28,45] The Ta fel slope of Pt nanocubes/C was8 9.4 mV dec À1 ,w hereas those of PN-1/C, PN-2/C, and PN-3/C were 65.3, 45.0, and 64.8 mV dec À1 ,r espectively ( Figure 4B).…”

Nanocatalysts for Electrocatalytic Oxidation of Ethanol

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