Building Blocks Selected via a Rational Design Strategy for Developing POM-Based MOFs with Enhanced Proton Conductivity
Designing and synthesizing polyoxometalate-based metal-organic frameworks (POMOFs) with high proton conductivity is highly significant yet challenging. An effective strategy for developing highly proton-conductive POMOFs involves using polyoxometalates (POMs) with specific acid dissociation constants (p<i>K</i><sub>a</sub>), which reflect the ability of an acid to donate protons and serve as a key parameter for proton conduction. Herein, two Anderson-type POMs, (NH<sub>4</sub>)<sub>3</sub>[AlMo<sub>6</sub>O<sub>24</sub>H<sub>6</sub>]·7H<sub>2</sub>O (AlMo<sub>6</sub>) and (NH<sub>4</sub>)<sub>3</sub>[CrMo<sub>6</sub>O<sub>24</sub>H<sub>6</sub>]·7H<sub>2</sub>O (CrMo<sub>6</sub>), whose p<i>K</i><sub>a</sub> values were determined via DFT calculation. The reliability of these calculated p<i>K</i><sub>a</sub> values was confirmed by a strong correlation with experimentally measured proton conductivities under humidified conditions. Using these POMs, along with metal-organic frameworks under hydrothermal conditions, we synthesized two isostructural POMOFs, denoted as CUST-835 (AlMo<sub>6</sub>) and CUST-836 (CrMo<sub>6</sub>). Alternating current (AC) impedance studies reveal that CUST-835 achieves a proton conductivity of 2.06 × 10<sup>-4</sup> S cm<sup>-1</sup> at 90 °C and 98% RH, an order of magnitude higher than that of CUST-836 (1.11 × 10<sup>-5</sup> S cm<sup>-1</sup>).
Authors
- Xingqi Han (ORCID: https://orcid.org/0000-0002-9479-9970)
- Xue-Song Wu (ORCID: https://orcid.org/0000-0001-5044-5719)
- Yu Tian (ORCID: https://orcid.org/0000-0003-4422-4762)
- Xinlong Wang (ORCID: https://orcid.org/0000-0002-5758-6351)
- Zhong‐Min Su (ORCID: https://orcid.org/0000-0002-3342-1966)
- Bao-Yue Zhang
- Ning-Hao Wang
Institutions
- Changchun University of Science and Technology (CN)
- Northeast Normal University (CN)
- Jilin University (CN)
- Hainan University (CN)
- Jilin Engineering Normal University (CN)
- Ministry of Education (IR)
- Institute of Theoretical Physics (CN)
- Jilin Province Science and Technology Department (CN)
- Jilin Medical University (CN)
- State Key Laboratory of Supramolecular Structure and Materials
Publication Details
- Journal
- Inorganic Chemistry
- Published
- 2025-09-26
- DOI
- https://doi.org/10.1021/acs.inorgchem.5c03333
- Citations
- 3
- Primary Topic
- Metal-Organic Frameworks: Synthesis and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.61