Superprotonic Conductivity of a UiO-66 Framework Functionalized with Sulfonic Acid Groups by Facile Postsynthetic Oxidation

• Published in: Angewandte Chemie International Edition Vol. 54; no. 17; pp. 5142 - 5146
• Main Authors: Phang, Won Ju, Jo, Hyuna, Lee, Woo Ram, Song, Jeong Hwa, Yoo, Kicheon, Kim, BongSoo, Hong, Chang Seop
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 20-04-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Backbone; Covalence; Decoration; Electrolytes; Equivalence; metal-organic frameworks; Oxidation; postsynthetic oxidation; proton-conducting materials; Relative humidity; Stability; Sulfonic acid; sulfonic acid groups; thiol groups; postsynthetic oxidation; proton-conducting materials; sulfonic acid groups; thiol groups; metal-organic frameworks
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201411703

Facile postsynthetic oxidation of the thiol‐laced UiO‐66‐type framework UiO‐66(SH)2 enabled the generation of UiO‐66(SO3H)2 with sulfonic acid groups covalently linked to the backbone of the system. The oxidized material exhibited a superprotonic conductivity of 8.4×10−2 S cm−1 at 80 °C and 90 % relative humidity, and long‐term stability of the conductivity was observed. This level of conductivity exceeds that of any proton‐conducting MOF reported to date and is equivalent to the conductivity of the most effective known electrolyte, Nafion.
Decorated for honorable conductivity: The postsynthetic oxidation of a thiol‐laced UiO‐66‐type framework generated sulfonic acid groups covalently linked to the backbone of the system (see picture; green circles are ZrO nodes). The oxidized material exhibited stable superprotonic conductivity of 8.4×10−2 S cm−1 at 80 °C and 90 % relative humidity.