Water oxidation is the prerequisite for dioxygen evolution in natural or artificial photosynthesis. Although it has been demonstrated that multinuclear active sites are commonly necessary for water oxidation, as inspired by the natural oxygen-evolving centre CaMn4O5, a multinuclear manganese cluster, whether mononuclear manganese can also efficiently catalyse water oxidation has been a long-standing question. Herein, we found that a heterogeneous catalyst with mononuclear manganese embedded in nitrogen-doped graphene (Mn-NG) shows a turnover frequency as high as 214 s−1 for chemical water oxidation and an electrochemical overpotential as low as 337 mV at a current density of 10 mA cm−2. Structural characterization and density functional theory calculations reveal that the high activity of Mn-NG can be attributed to the mononuclear manganese ion coordinated with four nitrogen atoms embedded in the graphene matrix.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $8.67 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Bard, A. J. & Fox, M. A. Artificial photosynthesis—solar splitting of water to hydrogen and oxygen. Acc. Chem. Res. 28, 141–145 (1995).
Yano, J. & Yachandra, V. Mn4Ca cluster in photosynthesis: where and how water is oxidized to dioxygen. Chem. Rev. 114, 4175–4205 (2014).
Ogata, K., Yuki, T., Hatakeyama, M., Uchida, W. & Nakamura, S. All-atom molecular dynamics simulation of photosystem II embedded in thylakoid membrane. J. Am. Chem. Soc. 135, 15670–15673 (2013).
Yang, J., Wang, D., Han, H. & Li, C. Roles of cocatalysts in photocatalysis and photoelectrocatalysis. Acc. Chem. Res. 46, 1900–1909 (2013).
Spoeri, C., Kwan, J. T. H., Bonakdarpour, A., Wilkinson, D. P. & Strasser, P. The stability challenges of oxygen evolving catalysts: towards a common fundamental understanding and mitigation of catalyst degradation. Angew. Chem. Int. Ed. 56, 5994–6021 (2017).
Dismukes, G. C. et al. Development of bioinspired Mn4O4-cubane water oxidation catalysts: lessons from photosynthesis. Acc. Chem. Res. 42, 1935–1943 (2009).
Garrido-Barros, P., Gimbert-Surinach, C., Matheu, R., Sala, X. & Llobet, A. How to make an efficient and robust molecular catalyst for water oxidation. Chem. Soc. Rev. 46, 6088–6098 (2017).
Limburg, J. et al. A functional model for O–O bond formation by the O2-evolving complex in photosystem II. Science 283, 1524–1527 (1999).
Yagi, M. & Narita, K. Catalytic O2 evolution from water induced by adsorption of [(OH2)(terpy)Mn(μ-O)2Mn(terpy)(OH2)]3+ complex onto clay compounds. J. Am. Chem. Soc. 126, 8084–8085 (2004).
Kanady, J. S., Tsui, E. Y., Day, M. W. & Agapie, T. A synthetic model of the Mn3Ca subsite of the oxygen-evolving complex in photosystem II. Science 333, 733–736 (2011).
Hocking, R. K. et al. Water-oxidation catalysis by manganese in a geochemical-like cycle. Nat. Chem. 3, 461–466 (2011).
Chen, H. Y., Faller, J. W., Crabtree, R. H. & Brudvig, G. W. Dimer-of-dimers model for the oxygen-evolving complex of photosystem II. Synthesis and properties of [Mniv 4O5)(terpy)4(H2O)2](ClO4)6. J. Am. Chem. Soc. 126, 7345–7349 (2004).
Ruettinger, W. F., Campana, C. & Dismukes, G. C. Synthesis and characterization of Mn4O4L6 complexes with cubane-like core structure: a new class of models of the active site of the photosynthetic water oxidase. J. Am. Chem. Soc. 119, 6670–6671 (1997).
Zhang, C. et al. A synthetic Mn4Ca-cluster mimicking the oxygen-evolving center of photosynthesis. Science 348, 690–693 (2015).
Schwarz, B. et al. Visible-light-driven water oxidation by a molecular manganese vanadium oxide cluster. Angew. Chem. Int. Ed. 55, 6329–6333 (2016).
Maayan, G., Gluz, N. & Christou, G. A bioinspired soluble manganese cluster as a water oxidation electrocatalyst with low overpotential. Nat. Catal. 1, 48–54 (2018).
Xu, Y. et al. Chemical and light-driven oxidation of water catalyzed by an efficient dinuclear ruthenium complex. Angew. Chem. Int. Ed. 49, 8934–8937 (2010).
Gersten, S. W., Samuels, G. J. & Meyer, T. J. Catalytic-oxidation of water by an oxo-bridged ruthenium dimer. J. Am. Chem. Soc. 104, 4029–4030 (1982).
Duan, L., Wang, L., Li, F., Li, F. & Sun, L. Highly efficient bioinspired molecular Ru water oxidation catalysts with negatively charged backbone ligands. Acc. Chem. Res. 48, 2084–2096 (2015).
Yin, Q. et al. A fast soluble carbon-free molecular water oxidation catalyst based on abundant metals. Science 328, 342–345 (2010).
Okamura, M. et al. A pentanuclear iron catalyst designed for water oxidation. Nature 530, 465–468 (2016).
Shaffer, D. W., Xie, Y. & Concepcion, J. J. O–O bond formation in ruthenium-catalyzed water oxidation: single-site nucleophilic attack vs. O–O radical coupling. Chem. Soc. Rev. 46, 6170–6193 (2017).
Meyer, T. J., Sheridan, M. V. & Sherman, B. D. Mechanisms of molecular water oxidation in solution and on oxide surfaces. Chem. Soc. Rev. 46, 6148–6169 (2017).
Ma, L. et al. Cerium(iv)-driven water oxidation catalyzed by a manganese(v)-nitrido complex. Angew. Chem. Int. Ed. 54, 5246–5249 (2015).
Ellis, W. C., McDaniel, N. D., Bernhard, S. & Collins, T. J. Fast water oxidation using iron. J. Am. Chem. Soc. 132, 10990–10991 (2010).
Duan, L. et al. A molecular ruthenium catalyst with water-oxidation activity comparable to that of photosystem II. Nat. Chem. 4, 418–423 (2012).
Hull, J. F. et al. Highly active and robust Cp* iridium complexes for catalytic water oxidation. J. Am. Chem. Soc. 131, 8730–8731 (2009).
Lee, W.-T., Munoz, S. B., Dickie, D. A. & Smith, J. M. Ligand modification transforms a catalase mimic into a water oxidation catalyst. Angew. Chem. Int. Ed. 53, 9856–9859 (2014).
Sun, Y., Hu, X., Luo, W., Xia, F. & Huang, Y. Reconstruction of conformal nanoscale MnO on graphene as a high-capacity and long-life anode material for lithium ion batteries. Adv. Funct. Mater. 23, 2436–2444 (2013).
Xue, Y. et al. Low temperature growth of highly nitrogen-doped single crystal graphene arrays by chemical vapor deposition. J. Am. Chem. Soc. 134, 11060–11063 (2012).
Schnegg, A. et al. Probing the fate of Mn complexes in Nafion: a combined multifrequency EPR and XAS study. J. Phys. Chem. C 120, 853–861 (2016).
Colmer, H. E., Howcroft, A. W. & Jackson, T. A. Formation, characterization, and O–O bond activation of a peroxomanganese(iii) complex supported by a cross-clamped cyclam ligand. Inorg. Chem. 55, 2055–2069 (2016).
Gallagher, A. T. et al. A structurally-characterized peroxomanganese(iv) porphyrin from reversible O2 binding within a metal-organic framework. Chem. Sci. 9, 1596–1603 (2018).
He, M., Li, X., Liu, Y. & Li, J. Axial Mn–C–CN bonds of cyano manganese(ii) porphyrin complexes: flexible and weak? Inorg. Chem. 55, 5871–5879 (2016).
Fei, H. et al. General synthesis and definitive structural identification of MN4C4 single-atom catalysts with tunable electrocatalytic activities. Nat. Catal. 1, 63–72 (2018).
Zitolo, A. et al. Identification of catalytic sites for oxygen reduction in iron-and nitrogen-doped graphene materials. Nat. Mater. 14, 937–942 (2015).
Li, Y.-Y., Ye, K., Siegbahn, P. E. M. & Liao, R.-Z. Mechanism of water oxidation catalyzed by a mononuclear manganese complex. ChemSusChem 10, 903–911 (2017).
Norskov, J. K. et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J. Phys. Chem. B 108, 17886–17892 (2004).
Man, I. C. et al. Universality in oxygen evolution electrocatalysis on oxide surfaces. ChemCatChem 3, 1159–1165 (2011).
Garcia-Mota, M. et al. Importance of correlation in determining electrocatalytic oxygen evolution activity on cobalt oxides. J. Phys. Chem. C 116, 21077–21082 (2012).
Su, H.-Y. et al. Identifying active surface phases for metal oxide electrocatalysts: a study of manganese oxide bi-functional catalysts for oxygen reduction and water oxidation catalysis. Phys. Chem. Chem. Phys. 14, 14010–14022 (2012).
Xu, H., Cheng, D., Cao, D. & Zeng, X. C. A universal principle for a rational design of single-atom electrocatalysts. Nat. Catal. 1, 339–348 (2018).
Fernando, A. & Aikens, C. M. Theoretical investigation of water oxidation catalysis by a model manganese cubane complex. J. Phys. Chem. C 120, 21148–21161 (2016).
Britt, R. D., Suess, D. L. M. & Stich, T. A. An Mn(v)-oxo role in splitting water? Proc. Natl Acad. Sci. USA 112, 5265–5266 (2015).
Busch, M., Ahlberg, E. & Panas, I. Electrocatalytic oxygen evolution from water on a Mn(iii–v) dimer model catalyst—a DFT perspective. Phys. Chem. Chem. Phys. 13, 15069–15076 (2011).
Siegbahn, P. E. M. Water oxidation mechanism in photosystem II, including oxidations, proton release pathways, O–O bond formation and O2 release. Biochim. Biophys. Acta Bioenergy 1827, 1003–1019 (2013).
Segre, C. U. et al. The MRCAT insertion device beamline at the Advanced Photon Source. AIP Conf. Proc. 521, 419–422 (2000).
Stern, E. A., Elam, W. T., Bunker, B. A., Lu, K. Q. & Heald, S. M. Ion chambers for fluorescence and laboratory EXAFS detection. Nucl. Instrum. Methods Phys. Res. 195, 345–346 (1982).
Ravel, B. N. M. & Newville, M. Data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrotron Radiat. 12, 537–541 (2005).
Stern, E. A., Heald, S. M. & Koch, E. Handbook on Synchrotron Radiation (North-Holland, Amsterdam, 1983).
Kresse, G. & Hafner, J. Abinitio molecular-dynamics for liquid-metals. Phys. Rev. B 47, 558–561 (1993).
Kresse, G. & Furthmuller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).
Perdew, J. P. & Wang, Y. Accurate and simple analytic representation of the electron-gas correlation-energy. Phys. Rev. B 45, 13244–13249 (1992).
Blochl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).
Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).
Kwapien, K., Piccinin, S. & Fabris, S. Energetics of water oxidation catalyzed by cobalt oxide nanoparticles: assessing the accuracy of DFT and DFT plus U approaches against coupled cluster methods. J. Phys. Chem. Lett. 4, 4223–4230 (2013).
Wang, L.-P. & Van Voorhis, T. Direct-coupling O2 bond forming a pathway in cobalt oxide water oxidation catalysts. J. Phys. Chem. Lett. 2, 2200–2204 (2011).
Li, X. & Siegbahn, P. E. Water oxidation mechanism for synthetic Co–oxides with small nuclearity. J. Am. Chem. Soc. 135, 13804–13813 (2013).
Mathew, K., Sundararaman, R., Letchworth-Weaver, K., Arias, T. & Hennig, R. G. Implicit solvation model for density-functional study of nanocrystal surfaces and reaction pathways. J. Chem. Phys. 140, 084106 (2014).
Dudarev, S. L., Botton, G. A., Savrasov, S. Y., Humphreys, C. J. & Sutton, A. P. Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA + U study. Phys. Rev. B 57, 1505–1509 (1998).
Heyd, J., Scuseria, G. E. & Ernzerhof, M. Hybrid functionals based on a screened Coulomb potential. J. Chem. Phys. 118, 8207–8215 (2003).
Krukau, A. V., Vydrov, O. A., Izmaylov, A. F. & Scuseria, G. E. Influence of the exchange screening parameter on the performance of screened hybrid functionals. J. Chem. Phys. 125, 224106 (2006).
Grant, R. W., Geller, S., Cape, J. A. & Espinosa, G. P. Magnetic and crystallographic transitions in α-Mn2O3–Fe2O3 system. Phys. Rev. 175, 686–695 (1968).
Busch, M., Ahlberg, E. & Panas, I. Hydroxide oxidation and peroxide formation at embedded binuclear transition metal sites; TM = Cr, Mn, Fe, Co. Phys. Chem. Chem. Phys. 13, 15062–15068 (2011).
Yancey, D. F. et al. A theoretical and experimental examination of systematic ligand-induced disorder in Au dendrimer-encapsulated nanoparticles. Chem. Sci. 4, 2912–2921 (2013).
Duan, Z. et al. A combined theoretical and experimental EXAFS study of the structure and dynamics of Au 147 nanoparticles. Catal. Sci. Technol. 6, 6879–6885 (2016).
Zabinsky, S., Rehr, J., Ankudinov, A., Albers, R. & Eller, M. Multiple-scattering calculations of X-ray-absorption spectra. Phys. Rev. B 52, 2995–3009 (1995).
Hu, X. L., Piccinin, S., Laio, A. & Fabris, S. Atomistic structure of cobalt-phosphate nanoparticles for catalytic water oxidation. ACS Nano 6, 10497–10504 (2012).
Chen, Z. et al. Amorphous cobalt oxide nanoparticles as active water-oxidation catalysts. ChemCatChem 9, 3641–3645 (2017).
Guan, J. et al. CoOx nanoparticle anchored on sulfonated-graphite as efficient water oxidation catalyst. Chem. Sci. 8, 6111–6116 (2017).
Guan, J. et al. Synthesis and demonstration of subnanometric iridium oxide as highly efficient and robust water oxidation catalyst. ACS Catal. 7, 5983–5986 (2017).
This work was supported by the National Natural Science Foundation of China (No. 21633010), the 973 National Basic Research Program of China (No. 2014CB239403), the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB17000000) and Honeywell UOP research cooperation (No. 13C0008). Special acknowledgement goes to the assistance of M. Charochak of UOP and J. Wright of IIT for assistance with data collection at MRCAT, and S. Pennycook of NUS for providing the HAADF-STEM device.
Supplementary Figures 1–29, Supplementary Tables 1–5, Supplementary Note 1, Supplementary Methods and Supplementary References