Numerical analysis of anion-exchange membrane direct glycerol fuel cells under steady state and dynamic operations

PdAg/CNT catalyzed alcohol oxidation reaction for high-performance anion exchange membrane direct alcohol fuel cell (alcohol = methanol, ethanol, ethylene glycol and glycerol)

“…[2] Anion exchange membrane DAFCs (AEM-DAFCs) are attracting increasing research efforts as a result of the fast kinetics of anode alcohol oxidation reaction (AOR) and cathode oxygen reduction reaction (ORR) in alkaline media. [3] Although non-precious iron-based catalysts [4][5][6] or carbon based metal-free catalysts [7,8] can be used for ORR at the cathode side in anion exchange membrane fuel cells (AEMFCs), high loading precious metal is still required for AOR at the anode side in low-temperature AEM-DAFCs. As a result, the cost of catalyst layer accounts for more than 50 % of the total cost of AEM-DAFCs [9], constituting a major technical obstacle hindering the commercialization of AEM-DAFCs.…”

“…In the electrochemical AOR process, carbonyl groups are detected on the surface of electrodes by infrared spectroscopy (IR) [29][30][31][32] while carboxylic groups are detected in the liquid electrolyte containing reaction products by high-performance liquid chromatography (HPLC) [5,33,34]. The aldehyde is considered to be either an intermediate or a reaction product of electrocatalytic AOR.…”

“…Peak power density per mass (Pt, Pd, Au) versus total Pt, Pd, Au loading in the MEA is exhibited for the major DAFCs systems including direct methanol fuel cells (DMFCs)[65][66][67][68][69][70][71][72][73][74][75][76], direct ethanol fuel cells (DEFCs)[1,12,, direct ethylene glycol fuel cells (DEGFCs)[13,68,[119][120][121][122], and direct glycerol fuel cells (DGFCs)[5,14,68,101,[123][124][125].Figure 6 summarizes the state-of-the-art performances of low temperature (< 100 ºC) oxygen or air based DAFCs fed with methanol, ethanol, ethylene glycol, and glycerol. In the current work, the PPDs per mass catalyst reach 270.2 mW mg Pd per MEA -1 , 404.6 mW mg Pd per MEA -1 , 490.4 mW mg Pd per MEA -1 and 552.4 mW mg Pd per MEA -1 for DMFC, DEFC, DEGFC, and DGFC, which are among the highest published results.…”

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

“…The influence of some fuel cell operating parameters such as glycerol and hydroxyl anions concentrations in fuel solution, and cell working temperature, on ADGFC performance have been evaluated. The dependence of the x-2 M OH − concentration maximum power density ratio (MPD xMOH /MPD 2MOH ) of ADGFCs on OH − concentration in fuel solutions with 1 M GLY from different datasets [13,54,124,125,128] is shown in Figure 8a. As can be seen in Figure 8a, the MPD xMOH /MPD 2MOH ratio increases with increasing hydroxyl anions concentration up to an OH − concentration of 8 M, where it reaches a near constant value.…”

“…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.…”