Performance of a Direct Glycerol Fuel Cell using KOH Doped Polybenzimidazole as Electrolyte

KOH-doped polybenzimidazole for alkaline direct glycerol fuel cells

“…6 displays the values of the glycerol permeability for the PBI membranes equilibrated in a 4 mol L À 1 KOH solution at different temperatures and glycerol concentrations. This KOH concentration was chosen according to previous results obtained for a DGFC by this research group [28]. As can be seen, the glycerol permeability at room temperature is around 2 Â 10 À 7 cm 2 s À 1 , which is close to that reported for other alcohols [20,21,42].…”

“…Most of the research on PBI has been focused on H 3 PO 4 doping, for high temperature PEMFC [15][16][17][18]. Nevertheless, PBI can also be doped with KOH, achieving good performances when operating with hydrogen [19] or with alcohols [13,[20][21][22][23][24][25][26][27][28] as fuel. Furthermore, more recent studies have proposed the modification of the base polymer in order to improve its properties: (a) by providing anionic exchange groups by alkylating the polymer backbone [29][30][31], (b) by combining it with ionic liquids [32] and carbon nanotubes [27], and (c) using a thermal curing process [33], among the most important alternatives.…”

“…Therefore, any alternative for glycerol valorization is welcomed, especially in a market such as the Brazilian one, where biodiesel occupies a large percentage of the diesel market [34]. The oxidation of glycerol in an alkaline environment has been proved to be especially favourable [35], and so has electrochemical oxidation (in a fuel cell), with very promising results in terms of power and added value products [6,7,28,36,37]. Moreover, in practical terms these advantages are accompanied by a significant weight of fundamental knowledge, accumulated over the last decade, on the glycerol electro-oxidation process [38][39][40][41].…”

Liquid fuel cells

“…A direct glycerol fuel cell fed with glycerol (1 M) in KOH (4 M) using a polybenzimidazole (PBI) membrane impregnated with KOH and PtRu/C and Pt 3 Sn/C anode catalysts showed a peak power density of 18 mW/cm 2 at 60 °C, which decreased as the temperature increased to 90 °C [113]. Pd-based electrocatalysts showed a much higher activity than Pt-based ones, e.g., PtRu, which is widely used in DMFCs [114].…”

Glycerol Electro-Oxidation in Alkaline Media and Alkaline Direct Glycerol Fuel Cells

“…So, the near constant MPD values for OHvalues > 8 M OH − can be explained by these simultaneous counteracting effects of OH − . The dependence of the x-1 M GLY concentration maximum power density ratio (MPDxMGLY/MPD1MGLY) of ADGFCs on glycerol concentration in fuel solution from different datasets [54,124,125,128,131] is shown in Figure 8b. As can be seen in Figure 8b, the Moreover, high KOH concentrations can neutralize the organic acid generated during the glycerol oxidation process, maintaining the local OH − concentration to a level adequate for continuous glycerol oxidation.…”