Abstract Ce/carbonaceous matrices-based composites with potential application in electrochemical processes were successfully produced. Ce-based MOF-76 (Metal Organic-Framework-76 family, formed by lanthanide ions coordinated to 1,3,5-benzenetricarboxylic acid ligand - H3BTC or simply BTC) was prepared with different percentages of graphene oxide (GO) in situ (named Ce-BTC-GOX%), then calcined to CeO2-rGOX%. All obtained materials were characterized by physicochemical techniques. The presence of carbonaceous matrices in the composites improves their thermal stability, alters particles shape, and decreases their size. All materials underwent Cyclic Voltammetry tests and selected composites were evaluated by Electrochemical Impedance Spectroscopy, Hydrogen Evolution Reaction and Oxygen Evolution Reaction. The electron transfer between Ce3+/Ce4+ redox pairs is observed around 1.3 and 1.2 V vs. Ag/AgCl(sat.KCl) for oxidation and reduction, respectively. Among all produced materials, the Ce-BTC-GO30% presented the best electrochemical response, reaching 0.506 mA g-1 of anodic current and 19.92 mC g-1 of charge density. Its capacitance reaches 3340.8 μF cm-2, while its resistance to charge transfer decreases (2.4 Ω cm2) and Tafel equation slopes are 84.3 mV dec-1 for HER and 60.5/127.9 mV dec-1 for OER.

中文翻译：

---

Ce/碳基复合材料的物理化学和电化学表征

摘要 成功制备了在电化学过程中具有潜在应用价值的 Ce/碳基复合材料。用不同百分比的氧化石墨烯 (GO) 原位制备了基于 Ce 的 MOF-76（金属有机框架 76 家族，由镧系元素离子与 1,3,5-苯三甲酸配体 - H3BTC 或简单的 BTC 配位形成）。命名为 Ce-BTC-GOX%)，然后煅烧为 CeO2-rGOX%。所有获得的材料都通过物理化学技术进行表征。复合材料中碳质基质的存在提高了它们的热稳定性，改变了颗粒形状，并减小了它们的尺寸。所有材料都进行了循环伏安法测试，并通过电化学阻抗谱、析氢反应和析氧反应对选定的复合材料进行了评估。Ce3+/Ce4+ 氧化还原对之间的电子转移分别在 1.3 和 1.2 V 与 Ag/AgCl(sat.KCl) 的氧化和还原之间观察到。在所有生产的材料中，Ce-BTC-GO30% 表现出最好的电化学响应，达到 0.506 mA g-1 的阳极电流和 19.92 mC g-1 的电荷密度。其电容达到 3340.8 μF cm-2，而其电荷转移电阻降低 (2.4 Ω cm2)，Tafel 方程斜率对于 HER 为 84.3 mV dec-1，对于 OER 为 60.5/127.9 mV dec-1。