Kun Jiang1, Seoin Back2, Austin J Akey3, Chuan Xia1, Yongfeng Hu4, Wentao Liang5, Diane Schaak1, Eli Stavitski6, Jens K Nørskov2,7, Samira Siahrostami8,9, Haotian Wang10,11. 1. Rowland Institute, Harvard University, Cambridge, MA, 02142, USA. 2. SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. 3. Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA. 4. Canadian Light Source Inc., University of Saskatchewan, Saskatoon, SK, S7N 2V3, Canada. 5. Kostas Research Institute, Northeastern University, Burlington, MA, 01803, USA. 6. National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA. 7. SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. 8. SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. samira.siahrostami@ucalgary.ca. 9. Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada. samira.siahrostami@ucalgary.ca. 10. Rowland Institute, Harvard University, Cambridge, MA, 02142, USA. htwang@rice.edu. 11. Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, 77005, USA. htwang@rice.edu.
Abstract
Shifting electrochemical oxygen reduction towards 2e- pathway to hydrogen peroxide (H2O2), instead of the traditional 4e- to water, becomes increasingly important as a green method for H2O2 generation. Here, through a flexible control of oxygen reduction pathways on different transition metal single atom coordination in carbon nanotube, we discovered Fe-C-O as an efficient H2O2 catalyst, with an unprecedented onset of 0.822 V versus reversible hydrogen electrode in 0.1 M KOH to deliver 0.1 mA cm-2 H2O2 current, and a high H2O2 selectivity of above 95% in both alkaline and neutral pH. A wide range tuning of 2e-/4e- ORR pathways was achieved via different metal centers or neighboring metalloid coordination. Density functional theory calculations indicate that the Fe-C-O motifs, in a sharp contrast to the well-known Fe-C-N for 4e-, are responsible for the H2O2 pathway. This iron single atom catalyst demonstrated an effective water disinfection as a representative application.
Shifting electrochemical oxygen reduction town class="Chemical">ards 2e- pathway to hydrogen peroxide (H2O2), instead of the traditional 4e- to water, becomes increasingly important as a green method for H2O2 generation. Here, through a flexible control of oxygen reduction pathways on different transition metal single atom coordination in carbon nanotube, we discovered Fe-C-O as an efficient H2O2 catalyst, with an unprecedented onset of 0.822 V versus reversible hydrogen electrode in 0.1 M KOH to deliver 0.1 mA cm-2 H2O2 current, and a high H2O2 selectivity of above 95% in both alkaline and neutral pH. A wide range tuning of 2e-/4e- ORR pathways was achieved via different metal centers or neighboring metalloid coordination. Density functional theory calculations indicate that the Fe-C-O motifs, in a sharp contrast to the well-known Fe-C-N for 4e-, are responsible for the H2O2 pathway. This iron single atom catalyst demonstrated an effective water disinfection as a representative application.