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Increased Hydrogen Production of Perovskite Solar Thermochemical Water Splitters by Joint Reduction on A and B Sites

ORAL

Abstract

Oxide based solar-thermochemical hydrogen (STCH) production operates by cyclic creation of oxygen vacancies that then react with steam to produce hydrogen. STCH performance is strongly dependent on both the change in vacancy stoichiometry (��) during cycling (����) and the output gas ratio of H2/H2O. Perovskites (ABO3) have been investigated by controlled synthesis and X-ray adsorption spectroscopy (XAS) as STCH oxides in-part due to their tunable cation-dependent oxygen vacancy enthalpies. Classically, only one site, either A or B, has been responsible for charge compensation of oxygen vacancies. However, in this work we investigate water splitting by computationally designed perovskites expected to possess dual reduction on both A and B sites, which is predicted to increase vacancy formation, and hence performance, through increased formation entropy of vacancies. In-operando X-ray absorption spectroscopy (XAS) results at Ce L-edge and Mn and V K- and L-edges will demonstrate changing oxidation states of A and B site elements. Additional in-operando diffraction and mass loss experiments will correlate ���� and structural changes with cation reduction. This work will demonstrate the effectiveness of dual site reduction as a design criterion for STCH material design.

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Presenters

  • Robert Bell

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory & Colorado School of Mines, National Renewable Energy Laboratory

Authors

  • Robert Bell

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory & Colorado School of Mines, National Renewable Energy Laboratory

  • Sarah Shulda

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory

  • Dan Plattenberger

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory

  • Sai Gautam Gopalakrishnan

    Mechanical and Aerospace Engineering, Princeton University, Princeton, Princeton University

  • Nicholas Strange

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory & Colorado School of Mines, National Renewable Energy Laboratory

  • Philip Anthony Parilla

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory

  • Emily Carter

    Office of the Chancellor, University of California Los Angeles, University of California, Los Angeles, UCLA, Office of Chancellor, University of California Los Angeles, Office of the Chancellor, University of California, Los Angeles

  • Anthony McDaniel

    Sandia National Laboratory

  • Ellen B Stechel

    ASU Lightworks® and the School of Molecular Sciences, Arizona State University, Arizona State University

  • David S Ginley

    National Renewable Energy Laboratory & SLAC Linear Accelerator Laboratory, National Renewable Energy Laboratory