Proton exchange membrane fuel cells (PEMFCs) are one of a few technological solutions that address both alternative energy demands and sustainability (by virtually converting dihydrogen and O₂ to water).¹ With the prices of precious metals (e.g. Pt, Pd, Au) remaining high, the electrodes’ materials for this type of devices have to be cost-efficient in order to drive the technology into the marketplace. While the state–of–the–art solutions remain being platinum-based and carbon-supported, the alternatives are highly sought after. One of the potential solutions recognized by the community is to use earth-abundant metal (Ni, Co, Fe)-based systems.

The design of efficient functional materials often requires exploration of new modes of connectivity. In porous coordination materials, the nature of an organic linker plays a crucial role. Metal–organic frameworks have recently shown a well-received attention in addressing the need for new solutions in energy conversion and storage.^2-4

While symmetric linkers are widely employed, we show that a non-symmetric, electron-rich merged scaffold allows for fabrication of crystalline and amorphous metal-organic coordination networks. We have further utilized them to fabricate a non-supported material that shows high electrochemical oxygen reduction performance in alkaline medium with the onset and half-wave potential higher than that of the state-of-the-art 20 wt% Pt/C catalyst.

References

1. M. K. Debe, Electrocatalyst approaches and challenges for automotive fuel cells, Nature, 486, 43 (2012).
2. H. B. Wu and X. W. Lou, Metal-organic frameworks and their derived materials for electrochemical energy storage and conversion: Promises and challenges, Sci. Adv., 3, eaap9252 (2017).
3. P.-Q. Liao, J-Q. Shen, and J.-P. Zhang, Metal–organic frameworks for electrocatalysis, Coord. Chem. Rev., (2018) in press, DOI:10.1016/j.ccr.2017.09.001.
4. M. Shao, Q. Chang, J.-P. Dodelet, and R. Chenitz, Recent advances in electrocatalysts for oxygen reduction reaction, Chem. Rev., 116, 3594 (2016).