Winter, M. & Brodd, R. J. What are batteries, fuel cells, and supercapacitors? Chem. Rev. 104, 4245–4270 (2004).
Debe, M. K. Electrocatalyst approaches and challenges for automotive fuel cells. Nature 486, 43–51 (2012).
Cheng, F. & Chen, J. Metal–air batteries: from oxygen reduction electrochemistry to cathode catalysts. Chem. Soc. Rev. 41, 2172–2192 (2012).
Chen, A. & Holt-Hindle, P. Platinum-based nanostructured materials: synthesis, properties, and applications. Chem. Rev. 110, 3767–3804 (2010).
Gasteiger, H. A. & Markovic, N. M. Just a dream—or future reality? Science 324, 48–49 (2009).
Wang, Y. J. et al. Carbon-supported Pt-based alloy electrocatalysts for the oxygen reduction reaction in polymer electrolyte membrane fuel cells: particle size, shape, and composition manipulation and their impact to activity. Chem. Rev. 115, 3433–3467 (2015).
Tang, H. et al. Molecular architecture of cobalt porphyrin multilayers on reduced graphene oxide sheets for high-performance oxygen reduction reaction. Angew. Chem. Int. Ed. 52, 5585–5589 (2013).
Dai, L., Xue, Y., Qu, L., Choi, H. J. & Baek, J. B. Metal-free catalysts for oxygen reduction reaction. Chem. Rev. 115, 4823–4892 (2015).
Liu, X. & Dai, L. Carbon-based metal-free catalysts. Nat. Rev. Mater. 1, 16064 (2016).
Gong, K., Du, F., Xia, Z., Durstock, M. & Dai, L. Nitrogen-doped carbon nanotube arrays with high electrocatalytic activity for oxygen reduction. Science 323, 760–764 (2009).
Liang, J., Jiao, Y., Jaroniec, M. & Qiao, S. Z. Sulfur and nitrogen dual-doped mesoporous graphene electrocatalyst for oxygen reduction with synergistically enhanced performance. Angew. Chem. Int. Ed. 51, 11496–11500 (2012).
Yang, D.-S., Bhattacharjya, D., Inamdar, S., Park, J. & Yu, J.-S. Phosphorus-doped ordered mesoporous carbons with different lengths as efficient metal-free electrocatalysts for oxygen reduction reaction in alkaline media. J. Am. Chem. Soc. 134, 16127–16130 (2012).
Silva, R., Voiry, D., Chhowalla, M. & Asefa, T. Efficient metal-free electrocatalysts for oxygen reduction: polyaniline-derived N- and O-doped mesoporous carbons. J. Am. Chem. Soc. 135, 7823–7826 (2013).
Zhang, C., Mahmood, N., Yin, H., Liu, F. & Hou, Y. Synthesis of phosphorus-doped graphene and its multifunctional applications for oxygen reduction reaction and lithium ion batteries. Adv. Mater. 25, 4932–4937 (2013).
Zhao, Y. et al. Can boron and nitrogen co-doping improve oxygen reduction reaction activity of carbon nanotubes? J. Am. Chem. Soc. 135, 1201–1204 (2013).
Zhang, J., Zhao, Z., Xia, Z. & Dai, L. A metal-free bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions. Nat. Nanotech. 10, 444–452 (2015).
Li, Y. et al. An oxygen reduction electrocatalyst based on carbon nanotube–graphene complexes. Nat. Nanotech. 7, 394–400 (2012).
Liang, H. W., Zhuang, X., Bruller, S., Feng, X. & Mullen, K. Hierarchically porous carbons with optimized nitrogen doping as highly active electrocatalysts for oxygen reduction. Nat. Commun. 5, 4973 (2014).
Li, Q., Zhang, S., Dai, L. & Li, L.-S. Nitrogen-doped colloidal graphene quantum dots and their size-dependent electrocatalytic activity for the oxygen reduction reaction. J. Am. Chem. Soc. 134, 18932–18935 (2012).
Gottfried, J. M., Flechtner, K., Kretschmann, A., Lukasczyk, T. & Steinrück, H.-P. Direct synthesis of a metalloporphyrin complex on a surface. J. Am. Chem. Soc. 128, 5644–5645 (2006).
Zhang, C., Hao, R., Liao, H. & Hou, Y. Synthesis of amino-functionalized graphene as metal-free catalyst and exploration of the roles of various nitrogen states in oxygen reduction reaction. Nano Energy 2, 88–97 (2013).
Guo, D. et al. Active sites of nitrogen-doped carbon materials for oxygen reduction reaction clarified using model catalysts. Science 351, 361–365 (2016).
Li, J. et al. Graphdiyne: a metal-free material as hole transfer layer to fabricate quantum dot-sensitized photocathodes for hydrogen production. J. Am. Chem. Soc. 138, 3954–3957 (2016).
Wang, S. et al. A novel and highly efficient photocatalyst based on P25-graphdiyne nanocomposite. Small 8, 265–271 (2012).
Yang, N. et al. Photocatalytic properties of graphdiyne and graphene modified TiO2: from theory to experiment. ACS Nano 7, 1504–1512 (2013).
Ren, H. et al. A new graphdiyne nanosheet/Pt nanoparticle-based counter electrode material with enhanced catalytic activity for dye-sensitized solar cells. Adv. Energy Mater. 5, 1500296 (2015).
Parvin, N. et al. Few-layer graphdiyne nanosheets applied for multiplexed real-time DNA detection. Adv. Mater. 29, 1606755 (2017).
Tykwinski, R. R. Evolution in the palladium-catalyzed cross-coupling of sp- and sp
2-hybridized carbon atoms. Angew. Chem. Int. Ed. 42, 1566–1568 (2003).
Viola, A., Collins, J. J., Filipp, N. & Locke, J. S. Acetylenes as potential antarafacial components in concerted reactions. Formation of pyrroles from thermolyses of propargylamines, of a dihydrofuran from a propargylic ether, and of an ethylidenepyrrolidine from a β-amino acetylene. J. Org. Chem. 58, 5067–5075 (1993).
Liu, R. et al. Nitrogen-doped graphdiyne as a metal-free catalyst for high-performance oxygen reduction reactions. Nanoscale 6, 11336–11343 (2014).
Lv, Q. et al. Nitrogen-doped porous graphdiyne: a highly efficient metal-free electrocatalyst for oxygen reduction reaction. ACS Appl. Mater. Interfaces 9, 29744–29752 (2017).
Tobisu, M. & Chatani, N. Catalytic reactions involving the cleavage of carbon–cyano and carbon–carbon triple bonds. Chem. Soc. Rev. 37, 300–307 (2008).
Stankovich, S. et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon 45, 1558–1565 (2007).
Rimez, B., Rahier, H., Biesemans, M., Bourbigot, S. & Van Mele, B. Modelled decomposition mechanism of flame retarded poly(vinyl acetate) by melamine isocyanurate. J. Therm. Anal. Calorim. 127, 2315–2324 (2016).
Veselá, P. & Slovák, V. Monitoring of N-doped organic xerogels pyrolysis by TG-MS. J. Therm. Anal. Calorim. 113, 209–217 (2013).
Pham, C. V., Krueger, M., Eck, M., Weber, S. & Erdem, E. Comparative electron paramagnetic resonance investigation of reduced graphene oxide and carbon nanotubes with different chemical functionalities for quantum dot attachment. Appl. Phys. Lett. 104, 132102 (2014).
Lin, Z., Waller, G., Liu, Y., Liu, M. & Wong, C.-P. Facile synthesis of nitrogen-doped graphene via pyrolysis of graphene oxide and urea, and its electrocatalytic activity toward the oxygen-reduction reaction. Adv. Energy Mater. 2, 884–888 (2012).
Zhang, L. S., Liang, X. Q., Song, W. G. & Wu, Z. Y. Identification of the nitrogen species on N-doped graphene layers and Pt/NG composite catalyst for direct methanol fuel cell. Phys. Chem. Chem. Phys. 12, 12055–12059 (2010).
Zhong, J. et al. Probing solid state N-doping in graphene by X-ray absorption near-edge structure spectroscopy. Carbon 50, 335–338 (2012).
Li, X. et al. Simultaneous nitrogen doping and reduction of graphene oxide. J. Am. Chem. Soc. 131, 15939–15944 (2009).
Liang, Y. et al. Co3O4 Nanocrystals on graphene as a synergistic catalyst for oxygen reduction reaction. Nat. Mater. 10, 780–786 (2011).
Meng, C. et al. Atomically and electronically coupled Pt and CoO hybrid nanocatalysts for enhanced electrocatalytic performance. Adv. Mater. 29, 1604607 (2017).
Zhou, R., Zheng, Y., Jaroniec, M. & Qiao, S.-Z. Determination of the electron transfer number for the oxygen reduction reaction: from theory to experiment. ACS Catal. 6, 4720–4728 (2016).
Tang, W., Sanville, E. & Henkelman, G. A grid-based bader analysis algorithm without lattice bias. J. Phys. Condens. Matter 21, 084204 (2009).
Rossmeisl, J., Qu, Z. W., Zhu, H., Kroes, G. J. & Nørskov, J. K. Electrolysis of water on oxide surfaces. J. Electroanal. Chem. 607, 83–89 (2007).
Zhou, S., Liu, N., Wang, Z. & Zhao, J. Nitrogen-doped graphene on transition metal substrates as efficient bifunctional catalysts for oxygen reduction and oxygen evolution reactions. ACS Appl. Mater. Interfaces 9, 22578–22587 (2017).