Abstract
The oxygen reduction reaction (ORR) is under intense research due to its significance in energy storage and conversion processes. Recent studies show that interconnected and hierarchically porous structures can further enhance ORR kinetics as well as catalyst durability, but their preparation can be quite time and/or chemical consuming. Here, a simple approach is reported to prepare such complex structures by pyrolyzing composites containing NaCl and ZIF-8. The templating effect of molten NaCl connects ZIF-8 particles into web-like carbon networks. During ORR activity measurements, it achieves a 0.964 V onset potential and a 38 mV dec-1 Tafel slope, which are comparable to those of the benchmark Pt/C (0.979 V and 40 mV dec-1 ). Due to the metal-free feature, this catalyst exhibits a 16 mV shift in half-wave potential after a 10 000-cycle durability test, which is only 60% of that of Pt/C. The catalyst is also tested in Zn-air batteries and the assemblies are able to work at above 1.2 V for 140 h, which triples the life held by those with Pt/C. This study demonstrates a facile strategy to prepare metal-free ORR catalysts with interconnectivity and hierarchical porosity, and proves their great potentials in ORR catalysis and Zn-air batteries.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.