Enhancement of glucose electro-oxidation by an external electromagnetic field in direct-mode fuel cells

Towards an Efficient Direct Glucose Anion Exchange Membrane Fuel Cell System with Several Electro-Oxidation Units

“…Our reported tests with both the direct glucose cylinder and the rectangular (flat) type anion exchange membrane fuel cells (AEMFC) confirm previous results that at the most only two electrons are extracted during electrochemical oxidation of glucose in a near-neutral-state electrolyte [4][5][6]. Thus, it has to be admitted that a single fuel cell with a certain anode -cathode pair is ineffective for achieving a high degree of oxidation of glucose, which can theoretically provide the transfer of 24 electrons per molecule.…”

“…Very small amounts of glycolic and formic acids have been detected as well [12]. The measured pH-values in this work (Tab 5) are lower than the final pH values were for the cylinder shaped fuel cell with different concentrations of the fuel-electrolyte solutions tested in the temperature range from 20 to 37 o C [4][5]. This indicates increased formation of acidic oxidation products in the liquid phase as a result of the electrochemical oxidation of glucose.…”

“…While measuring the Coulombic efficiency, the heating of the cell to 37 o C caused evaporation of water despite water vapour was fed to the suction side of the air blower. The Coulombic efficiency values (CE, %, based on two electrons transfer) and the specific energy values (SPEC, Wh kg -1 glucose) were calculated according to our earlier reported works [4][5][6]. Distilled water was added occasionally in the pumping vessel to compensate the evaporation of the aqueous electrolyte as it is described in our earlier work [6].…”

“…4. From the literature, it can be concluded that the main oxidation product with Pt-derived anode electrodes is gluconic acid, but also glucuronic, glucaric, oxalic and tartaric acids can be formed [12,13].…”

“…Thus, from the results shown in Tables 4 and 5 it is possible to assume that by using the multi stage direct glucose fuel cell system it could be possible to achieve a higher specific energy values. To this end, more selective and active anode catalysts than those used here or earlier [4][5][6] are sought for the electro-oxidation of glucose and its intermediate products. The development of an effective multistage direct glucose fuel cell system have to contain an effective control system with load variations for the oxidation process itself and maintaining the pH of the fuel-electrolyte constant or near the starting value.…”