AUTHOR=Rautenberg Max , Gernhard Marius , Radnik Jörg , Witt Julia , Roth Christina , Emmerling Franziska 

TITLE=Mechanochemical Synthesis of Fluorine-Containing Co-Doped Zeolitic Imidazolate Frameworks for Producing Electrocatalysts

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.840758

DOI=10.3389/fchem.2022.840758

ISSN=2296-2646

ABSTRACT=<p>Catalysts derived from pyrolysis of metal organic frameworks (MOFs) are promising candidates to replace expensive and scarce platinum-based electrocatalysts commonly used in polymer electrolyte membrane fuel cells. MOFs contain ordered connections between metal centers and organic ligands. They can be pyrolyzed into metal- and nitrogen-doped carbons, which show electrocatalytic activity toward the oxygen reduction reaction (ORR). Furthermore, metal-free heteroatom-doped carbons, such as N-F-Cs, are known for being active as well. Thus, a carbon material with Co-N-F doping could possibly be even more promising as ORR electrocatalyst. Herein, we report the mechanochemical synthesis of two polymorphs of a zeolitic imidazole framework, Co-doped zinc 2-trifluoromethyl-1H-imidazolate (Zn<sub>0.9</sub>Co<sub>0.1</sub>(CF<sub>3</sub>-Im)<sub>2</sub>). Time-resolved <italic>in situ</italic> X-ray diffraction studies of the mechanochemical formation revealed a direct conversion of starting materials to the products. Both polymorphs of Zn<sub>0.9</sub>Co<sub>0.1</sub>(CF<sub>3</sub>-Im)<sub>2</sub> were pyrolyzed, yielding Co-N-F containing carbons, which are active toward electrochemical ORR.</p>