Vapor expansion growth of core–shell Cu[sbnd]O[sbnd]C catalysts to boost low temperature oxygen reduction catalysis.

Core-shell Cu O C catalysts were synthesized by a vapor-expansion route, which enhances their oxygen reduction catalysis. [Display omitted] • Challenging the dominated Cu N C catalysts, core–shell Cu O C catalysts was synthesized by a simple vapor expansion route. • The Cu O C catalysts have good ORR activities (onset potential: 0.895 V, halfwave potential: 0.837 V). • Cu 2 O active sites contribute to the synergistic catalysis of core–shell Cu O C catalysts. • The M O C (M refers to transition metals) catalysts will pave a new road to synthesize high-efficient catalysts for fuels cells. M N C (M refers to transition metals) catalysts are the most promising alternative candidates to replace the precious commercial Pt/C catalysts for fuel cells. Due to the high reaction energy barriers between M and N elements, however, a simple and effective route to form M−N x actives sites in M N C catalysts remains a big challenge. Herein we have developed a confined vapor expansion growth of core–shell Cu O C catalysts, which demonstrated good ORR activities (onset potential: 0.895 V, halfwave potential: 0.837 V) under 273–278 K low temperatures. Experimental and first-principles calculations results elucidated that Cu 2 O active sites were found on the copper core of core–shell Cu O C catalysts. By means of forming copper complex organometallics, C O, C O and Cu–O bonds between carbon shell and copper core of core–shell Cu O C catalysts were constructed, which contributed to their synergistic catalysis. Challenging the dominated M N C catalysts, the M O C design route will pave a new road to synthesize high-efficient and low-cost catalysts for fuels cells. [ABSTRACT FROM AUTHOR]