College of Chemistry and Green Catalysis Centre, Zhengzhou University, Zhengzhou 450001, Henan, P. R. China.
School of Science, North University of China, Taiyuan 030051, Shanxi, P. R. China.
Inorg Chem. 2022 Jun 27;61(25):9564-9579. doi: 10.1021/acs.inorgchem.2c00809. Epub 2022 Jun 14.
Hafnium (Hf)-based UiO-66 series metal-organic frameworks (MOFs) have been widely studied on gas storage, gas separation, reduction reaction, and other aspects since they were first prepared in 2012, but there are few studies on proton conductivity. In this work, one Hf-based MOF, Hf-UiO-66-fum showing UiO-66 structure, also known as , was synthesized at room temperature using cheap fumaric acid as the bridging ligand, and then imidazole units were successfully introduced into to obatin a doped product, . Note that both and demonstrate excellent thermal, water, and acid-base stabilities. Expectedly, the maximum proton conductivity (σ) of (1.46 × 10 S·cm) is nearly 4 times greater than that of (3.98 × 10 S·cm) under 100 °C and 98% relative humidity (RH). To explore their possible practical application value, we doped them into chitosan (CS) or Nafion membranes as fillers, namely, , , and (, , and are the doping percentages of MOF in the membrane, respectively). Intriguingly, it was found that and indicated the highest σ values of 1.73 × 10 and 2.14 × 10 S·cm, respectively, under 100 °C and 98% RH and also revealed a high σ value of 4.87 × 10 S·cm under 80 °C and 98% RH, which showed varying degrees of enhancement compared to the original MOFs or pure CS and Nafion membranes. Our study illustrates that these Hf-based MOFs and related composite membranes offer great potential in electrochemical fields.
铪（Hf）基 UiO-66 系列金属有机骨架（MOFs）自 2012 年首次制备以来，在气体存储、气体分离、还原反应等方面得到了广泛的研究，但对质子传导性的研究较少。在这项工作中，使用廉价的富马酸作为桥联配体，在室温下合成了一种 Hf 基 MOF，Hf-UiO-66-fum，其结构与 UiO-66 相同，也称为 ，然后成功地将咪唑单元引入 中以获得掺杂产物 。需要注意的是， 和 均表现出优异的热稳定性、水稳定性和酸碱稳定性。不出所料，在 100°C 和 98%相对湿度（RH）下， 的最大质子电导率（σ）（1.46×10 S·cm）比 的（3.98×10 S·cm）高近 4 倍。为了探索它们的实际应用价值，我们将它们掺杂到壳聚糖（CS）或 Nafion 膜中作为填料，即 、 、和 （、、和 分别是 MOF 在膜中的掺杂百分比）。有趣的是，发现 和 分别在 100°C 和 98%RH 下显示出最高的 σ 值为 1.73×10 和 2.14×10 S·cm，在 80°C 和 98%RH 下也显示出 4.87×10 S·cm 的高 σ 值，与原始 MOFs 或纯 CS 和 Nafion 膜相比，都有不同程度的提高。我们的研究表明，这些基于 Hf 的 MOFs 和相关的复合膜在电化学领域具有巨大的潜力。
