Roschger Michaela, Wolf Sigrid, Mayer Kurt, Billiani Andreas, Genorio Boštjan, Gorgieva Selestina, Hacker Viktor
Institute of Chemical Engineering and Environmental Technology, Graz University of Technology Inffeldgasse 25/C 8010 Graz Austria
Faculty of Chemistry and Chemical Technology, University of Ljubljana Večna pot 113 1000 Ljubljana Slovenia.
Sustain Energy Fuels. 2023 Jan 27;7(4):1093-1106. doi: 10.1039/d2se01729f. eCollection 2023 Feb 14.
Determining the optimum layer thickness, for the anode and cathode, is of utmost importance for minimizing the costs of the alkaline direct ethanol fuel cell (DEFC) without lowering the electrochemical performance. In this study, the influence of layer thickness on the performance of the ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR) in an alkaline medium and resistance was investigated. The prepared gas diffusion electrodes (GDEs) were fully characterized, with scanning electron microscopy to determine the layer thickness and electrochemically in half-cell configuration. Cyclic voltammetry and polarization curve measurements were used to determine the oxidation and reduction processes of the metals, the electrochemical active surface area, and the activity towards the ORR and EOR. It was demonstrated that realistic reaction conditions can be achieved with simple and fast half-cell GDE measurements. Single cell measurements were conducted to evaluate the influence of factors, such as membrane or ethanol crossover. In addition, electrochemical impedance spectra investigation was performed to identify the effect of layer thickness on resistance. This successfully demonstrated that the optimal layer thicknesses and high maximum power density values (120 mW cm) were achieved with the Pt-free catalysts and membranes used.
确定阳极和阴极的最佳层厚度对于在不降低电化学性能的情况下使碱性直接乙醇燃料电池（DEFC）的成本降至最低至关重要。在本研究中，研究了层厚度对碱性介质中乙醇氧化反应（EOR）和氧还原反应（ORR）性能以及电阻的影响。对制备的气体扩散电极（GDE）进行了全面表征，通过扫描电子显微镜确定层厚度，并在半电池配置中进行电化学表征。采用循环伏安法和极化曲线测量来确定金属的氧化和还原过程、电化学活性表面积以及对ORR和EOR的活性。结果表明，通过简单快速的半电池GDE测量可以实现实际的反应条件。进行单电池测量以评估诸如膜或乙醇渗透等因素的影响。此外，进行了电化学阻抗谱研究以确定层厚度对电阻的影响。这成功证明了使用无铂催化剂和膜可实现最佳层厚度和高最大功率密度值（120 mW/cm²）。
