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This work was supported by a Funding Program for World-Leading Innovative R&D on Science and Technology from the Japan Society for the Promotion of Science. A part of this work was supported by a fund from the Element Strategy Initiative Project of the Ministry of Education, Culture, Sports and Science for Technology in Japan. Author contributions H.H. proposed the idea behind this research and M.H. and H.H. directed the entire project. M.K., Y.I., Y.Y., F.H., S.M., S.K., T.Y. and S-W.K. performed the synthesis, characterization and catalytic testing of Ru/C12A7:e2. All the authors discussed the results and commented on the study. M.K., M.H. and H.H. co-wrote the manuscript. Additional information Supplementary information is available in the online version of the paper. Reprints and permission information is available online at http://www.nature.com/reprints. Correspondence and requests for materials should be addressed to H.H. for C12A7:e2 and M.H. for reactions. Competing financial interests The authors declare no competing financial interests. NATURE CHEMISTRY DOI: 10.1038/NCHEM.1476 ARTICLES NATURE CHEMISTRY | ADVANCE ONLINE PUBLICATION | www.nature.com/naturechemistry 7 © 2012 Macmillan Publishers Limited. All rights reserved