The high cost and scarcity of noble metal catalysts, such as Pt, have hindered the hydrogen production from electrochemical water splitting, the oxygen reduction in fuel cells and batteries. Herein, we developed a simple template-free approach to three-dimensional porous carbon networks codoped with nitrogen and phosphorus by pyrolysis of a supermolecular aggregate of self-assembled melamine, phytic acid, and graphene oxide (MPSA/GO). The pyrolyzed MPSA/GO acted as the first metal-free bifunctional catalyst with high activities for both oxygen reduction and hydrogen evolution. Zn-air batteries with the pyrolyzed MPSA/GO air electrode showed a high peak power density (310 W g(-1) ) and an excellent durability. Thus, the pyrolyzed MPSA/GO is a promising bifunctional catalyst for renewable energy technologies, particularly regenerative fuel cells.

This is the accepted version of the paper.This version of the publication may differ from the final published version. sub-sample analyses we identify differences between entering developed and developing host countries in terms of the impact of home country government support and quality of host country institutions. Our findings help explain the puzzle concerning why EE firms have rapidly internationalized in a short period of time and do not follow the pattern predicted by classical IB theories. In comparison with studies from developed country contexts, our findings also highlight that the effect of home country support may be context specific. Permanent repository link

Owing to a production error, a number of values were incorrectly shown in Table 6 of this article. A corrected version of this table is given overleaf.

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