Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells

Abstract

Synthesis and characterization of quaternary PtRuIrSn/C electrocatalysts for direct ethanol fuel cells Fatih, K.; Neburchilov, V.; Alzate, V.; Neagu, R.; Wang, H. 195 (2010) [7168][7169][7170][7171][7172][7173][7174][7175] Contents lists available at ScienceDirect /C electrocatalysts were prepared by a known impregnation-reduction (borohydride) method. The microstructure and chemical composition were determined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The activity of the electrocatalysts for EOR was compared to commercial Pt 67 Ru 33 /C (HISPEC5000) using linear sweep voltammetry (LSV) based on similar Pt loading. The results of this study show that electrocatalyst composition with 10 and 20% Ir (wt.%) exhibit higher electrocatalytic activity than the commercial PtRu electrocatalyst. 10 Sn 30 /C exhibited both a higher performance with a specific power density of 29 mW mg Pt −1 without O 2 backpressure at the cathode and an excellent long-term stability in a DEFC operating at 90 • C. Journal of Power Sources Journal of Power SourcesCrown

Effect of operating parameters and anode diffusion layer on the direct ethanol fuel cell performance

“…Because of the importance of the electrochemical reaction kinetics in this system most of the research work has been focused on the anode catalyst. Platinum-tin based catalysts have shown the best initial performance for the ethanol electro-oxidation reaction (EOR) [1,2], while Pt-Sn containing Ir showed better long term performance [3]. Almost all of the catalysts applied to EOR showed very low CO 2 yields with acetic acid and acetaldehyde being the main oxidation products.…”

“…Almost all of the catalysts applied to EOR showed very low CO 2 yields with acetic acid and acetaldehyde being the main oxidation products. Efforts to increase the platinum-tin electrocatalytic activity and CO 2 selectivity include design of its microstructure [4], adding a third [5][6][7][8][9], and fourth catalyst component [3] and modifying the catalyst support [10][11][12].…”

PtSnIr/C anode electrocatalysts: promoting effect in direct ethanol fuel cells

“…This suggests that Sn might be inserted into the Pt and/or Ir crystal structures as an alloy, as reported in several studies. 1,13,18,19,26 The third component at 2θ / 67.58° (0.39175 nm) is close to Pt (220) reflection (2θ / 67.53° and 0.39075 nm), suggesting the possible segregation of a fraction of Pt. This is supported by the presence of components at 2θ / 46.28° and 81.78° of the other two reflections at 2θ / 45.85° and 80.69° (Pt, 2θ / 46.27° and 81.37°).…”

Fundamentals of Electrochemistry with Application to Direct Alcohol Fuel Cell Modeling

“…This produces a sharp reduction of the effective catalyst surface area, which also reduces cell performance [25,[40][41][42]. To mitigate this effect, binary Pt-based catalysts include a secondary metal, such as Sn or Ru [42][43][44][45][46][47][48][49][50][51][52]; the blockage of active sites is alleviated via a bifunctional mechanism that allows the absorption of hydroxyl groups at lower potentials on the secondary metal, thus favoring further oxidation of Pt-adsorbates blocking the active catalyst sites [53][54][55]. It is interesting to note that the problem of CO poisoning is not unique to DAFCs; low-temperature PEMFCs running on hydrogen have very low tolerance to impurities (e.g., CO) in the fuel, requiring very high purity hydrogen that is costly to produce.…”

“…Due to the multiple species involved, the reaction is slower and more complex than Reaction (3), which leads to significantly lower current densities in DMFCs than in hydrogen PEMFCs. As a result, complex and expensive catalyst compositions (Pt-Ru nanoparticles supported on high surface area carbon) must be used to minimize activation losses [42][43][44][45][46][47][48][49][50][51][52].…”