Stable iridium dinuclear heterogeneous catalysts supported on metal-oxide substrate for solar water oxidation

Yanyan Zhao; Ke R Yang; Zechao Wang; Xingxu Yan; Sufeng Cao; Yifan Ye; Qi Dong; Xizi Zhang; James E Thorne; Lei Jin; Kelly L Materna; Antonios Trimpalis; Hongye Bai; Sirine C Fakra; Xiaoyan Zhong; Peng Wang; Xiaoqing Pan; Jinghua Guo; Maria Flytzani-Stephanopoulos; Gary W Brudvig; Victor S Batista; Dunwei Wang

doi:10.1073/pnas.1722137115

Stable iridium dinuclear heterogeneous catalysts supported on metal-oxide substrate for solar water oxidation

Proc Natl Acad Sci U S A. 2018 Mar 20;115(12):2902-2907. doi: 10.1073/pnas.1722137115. Epub 2018 Mar 5.

Authors

Yanyan Zhao¹, Ke R Yang², Zechao Wang^{3

4}, Xingxu Yan^{5

6

7}, Sufeng Cao⁸, Yifan Ye⁹, Qi Dong¹, Xizi Zhang¹, James E Thorne¹, Lei Jin³, Kelly L Materna², Antonios Trimpalis⁸, Hongye Bai¹, Sirine C Fakra⁹, Xiaoyan Zhong⁴, Peng Wang^{5

6}, Xiaoqing Pan^{7

10}, Jinghua Guo⁹, Maria Flytzani-Stephanopoulos⁸, Gary W Brudvig¹¹, Victor S Batista¹¹, Dunwei Wang¹²

Affiliations

¹ Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467.
² Department of Chemistry, Yale Energy Sciences Institute, Yale University, New Haven, CT 06520.
³ Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
⁴ National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, China.
⁵ National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 210093 Nanjing, China.
⁶ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093 Nanjing, China.
⁷ Department of Chemical Engineering and Materials Science, University of California, Irvine, CA 92697.
⁸ Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155.
⁹ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
¹⁰ Department of Physics and Astronomy, University of California, Irvine, CA 92697.
¹¹ Department of Chemistry, Yale Energy Sciences Institute, Yale University, New Haven, CT 06520; gary.brudvig@yale.edu victor.batista@yale.edu dwang@bc.edu.
¹² Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467; gary.brudvig@yale.edu victor.batista@yale.edu dwang@bc.edu.

Abstract

Atomically dispersed catalysts refer to substrate-supported heterogeneous catalysts featuring one or a few active metal atoms that are separated from one another. They represent an important class of materials ranging from single-atom catalysts (SACs) and nanoparticles (NPs). While SACs and NPs have been extensively reported, catalysts featuring a few atoms with well-defined structures are poorly studied. The difficulty in synthesizing such structures has been a critical challenge. Here we report a facile photochemical method that produces catalytic centers consisting of two Ir metal cations, bridged by O and stably bound to a support. Direct evidence unambiguously supporting the dinuclear nature of the catalysts anchored on α-Fe₂O₃ is obtained by aberration-corrected scanning transmission electron microscopy (AC-STEM). Experimental and computational results further reveal that the threefold hollow binding sites on the OH-terminated surface of α-Fe₂O₃ anchor the catalysts to provide outstanding stability against detachment or aggregation. The resulting catalysts exhibit high activities toward H₂O photooxidation.

Keywords: STEM; catalyst; solar energy; spectroscopy; water splitting.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't