Earth-Abundant Metal Oxides for Anodic Reactions in Acidic Electrolytes

Citation

Moreno-Hernandez, Ivan A. (2019) Earth-Abundant Metal Oxides for Anodic Reactions in Acidic Electrolytes. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/XRN5-FV98. https://resolver.caltech.edu/CaltechTHESIS:06042019-235050436

Abstract

The development of electrochemical systems such as electrolyzers and photoelectrochemical devices in corrosive electrolytes has been limited by the lack of earth-abundant materials that are both stable in acidic electrolytes and efficiently utilize energy for electrochemical reactions. Chapter 1 introduces several of the challenges in developing earth-abundant materials for electrochemical systems in acidic electrolytes, such as electrocatalysts for the oxygen and the chlorine evolution reactions, and protective layers for photoanodes. Chapter 2 reports the electrochemical behavior of crystalline transition metal antimonates consisting of solid solutions of MnSb₂O₆ with NiSb₂O₆ for the oxygen evolution reaction in strongly acidic electrolytes. In Chapter 3, the crystalline transition metal antimonates NiSb₂O₆, CoSb₂O₆, and MnSb₂O₆ are investigated for the chlorine evolution reaction, and CoSb₂O₆ is found to exhibit activity and stability comparable to noble metal oxide electrocatalysts. Chapter 4 describes the development of earth-abundant SnO_x coatings as protective heterojunctions for planar Si photoanodes in corrosive electrolytes. Chapter 5 focuses on the development of conformal SnO_x coatings that form protective heterojunctions on Si microcone photoanodes. The work presented herein demonstrates several strategies towards the development of stable earth-abundant materials for efficient electrochemical and photoelectrochemical energy conversion in acidic electrolytes.

Thesis Files