Banti Angeliki, Papazisi Kalliopi Maria, Balomenou Stella, Tsiplakides Dimitrios
Physical Chemistry Laboratory, Chemistry Department, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
Chemical Process and Energy Resources Institute, Centre for Research and Technology Hellas, 570 01 Thessaloniki, Greece.
Molecules. 2023 Aug 2;28(15):5827. doi: 10.3390/molecules28155827.
Polymer electrolyte membrane (PEM) water electrolyzers suffer mainly from slow kinetics regarding the oxygen evolution reaction (OER). Noble metal oxides, like IrO and RuO, are generally more active for OER than metal electrodes, exhibiting low anodic overpotentials and high catalytic activity. However, issues like electrocatalyst stability under continuous operation and cost minimization through a reduction in the catalyst loading are of great importance to the research community. In this study, unsupported IrO of various particle sizes (different calcination temperatures) were evaluated for the OER and as anode electrodes for PEM water electrolyzers. The electrocatalysts were synthesized by the modified Adams method, and the effect of calcination temperature on the properties of IrO electrocatalysts is investigated. Physicochemical characterization was conducted using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurement, high-resolution transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. For the electrochemical performance of synthesized electrocatalysts in the OER, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were conducted in a typical three-cell electrode configuration, using glassy carbon as the working electrode, which the synthesized electrocatalysts were cast on in a 0.5 M HSO solution. The materials, as anode PEM water electrolysis electrodes, were further evaluated in a typical electrolytic cell using a Nafion115 membrane as the electrolyte and Pt/C as the cathode electrocatalyst. The IrO electrocatalyst calcined at 400 °C shows high crystallinity with a 1.24 nm particle size, a high specific surface area (185 m g), and a high activity of 177 mA cm at 1.8 V for PEM water electrolysis.
聚合物电解质膜（PEM）水电解槽主要受限于析氧反应（OER）的缓慢动力学。贵金属氧化物，如IrO和RuO，通常对OER的活性比金属电极更高，表现出低阳极过电位和高催化活性。然而，诸如连续运行下电催化剂的稳定性以及通过减少催化剂负载来实现成本最小化等问题，对研究界来说至关重要。在本研究中，评估了不同粒径（不同煅烧温度）的无载体IrO用于OER以及作为PEM水电解槽的阳极电极。通过改进的亚当斯方法合成了电催化剂，并研究了煅烧温度对IrO电催化剂性能的影响。使用X射线衍射（XRD）、布鲁诺尔-埃米特-泰勒（BET）表面积测量、高分辨率透射电子显微镜（TEM）和X射线光电子能谱（XPS）分析进行了物理化学表征。对于合成电催化剂在OER中的电化学性能，采用典型的三电极配置进行循环伏安法（CV）和线性扫描伏安法（LSV），使用玻碳作为工作电极，将合成的电催化剂浇铸在0.5 M HSO溶液中。作为阳极PEM水电解电极的材料，在典型的电解槽中使用Nafion115膜作为电解质，Pt/C作为阴极电催化剂进行了进一步评估。在400℃煅烧的IrO电催化剂表现出高结晶度，粒径为1.24 nm，比表面积高（185 m g），在1.8 V下用于PEM水电解时活性高达177 mA cm。
