Institution: | 1. State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029 China
These authors contributed equally to this work.;2. State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029 China;3. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China;4. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China |
Abstract: | To achieve practical application of fuel cell, it is vital to develop highly efficient and durable Pt-free catalysts. Herein, we prepare atomically dispersed ZnNC catalysts with Zn-Pyrrolic-N4 moieties and abundant mesoporous structure. The ZnNC-based anion-exchange membrane fuel cell (AEMFC) presents an ultrahigh peak power density of 1.63 and 0.83 W cm−2 in H2-O2 and H2-air (CO2-free), and also exhibits long-term stability with more than 120 and 100 h for H2-air (CO2-free) and H2-O2, respectively. Density functional calculations further unveil that the Zn-Pyrrolic-N4 structure is the origin of high activity of as-synthesized ZnNC catalyst, while the Zn-Pyridinic-N4 moiety is inactive for oxygen reduction reaction (ORR), which successfully explain the puzzle why most Zn-metal-organic framework -derived ZnNC catalysts in previous reports did not present good ORR activity because of their Zn-Pyridinic-N4 moieties. This work offers a new route for speeding up development of AEMFCs. |