Evaluation of Brønsted acidity and proton topology in Zr- and Hf-based metal-organic frameworks using potentiometric acid-base titration

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 4; no. 4; pp. 1479 - 1485
• Main Authors: Klet, Rachel C, Liu, Yangyang, Wang, Timothy C, Hupp, Joseph T, Farha, Omar K
• Format: Journal Article
• Language: English
• Published: United States Royal Society of Chemistry 01.01.2016
• Subjects: acidity; coordination polymers; protons; titration; topology; zirconium
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/c5ta07687k

Potentiometric acid-base titration is introduced as a method to evaluate p K a values (Brønsted acidity) of protons present in the nodes of water stable Zr 6 - and Hf 6 -based metal-organic frameworks (MOFs), including UiO-type MOFs, NU-1000, and MOF-808. p K a values were determined for the three typical types of protons present in these MOFs: μ 3 -OH, M-OH 2 , and M-OH (M = Zr, Hf). Additionally, the data was used to quantify defect sites resulting from either a surfeit or shortage of linkers in the MOFs and to provide information about the true proton topology of each material. Potentiometric acid-base titration is introduced as a method to evaluate p K a values (Brønsted acidity) of protons present in the nodes of water stable Zr 6 - and Hf 6 -based metal-organic frameworks (MOFs), including UiO-type MOFs, NU-1000, and MOF-808.