Chemistry of Seawater Electrolysis and Byproduct Management for Underwater Breathing

Abstract

Underwater diving operations present the challenge that oxygen is not naturally abundant, thus presenting an impediment to human existence, performance and health. Oxygen may be produced from seawater, in principle, by electrolysis but it must be done so selectively and it needs to be generated at rates needed for human breathing. Additionally, for the purposes of optimized performance, the hydrogen produced as a byproduct of seawater electrolysis must be managed. These challenges define several basic science directions of exploration, which this proposal addresses. Specific objectives of the proposal are to generate oxygen at metabolic usage rates and to manage the hydrogen byproduct from seawater electrolysis by combining it with respired carbondioxide. Research will target the discovery of multicomponent water splitting catalysts and catalyst morphologies with the goal of delivering oxygen at the rates required for underwater diving missions. The hydrogen produced as a byproduct of seawater electrolysis will be combined with respired carbon dioxide to produce solubilized products that may be directly released into the ocean, thus eliminating the need for a rebreather. Two research tracks will be undertaken to produce seawater-soluble (i) formate from combination of carbon dioxide with hydrogen and (ii) C2 products via the formation of oxalate and then its subsequent reaction with hydrogen. The success of the proposed work provides a scientific underpinning for creating a closed loop breathing cycle for underwater diving operations.

Document Details

Document Type
DoD Grant Award
Publication Date
Jun 13, 2019
Source ID
N000141912385

Entities

People

  • Daniel G. Nocera

Organizations

  • Office of Naval Research
  • President and Fellows of Harvard College
  • United States Navy

Tags

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science
  • Systems Analysis and Design