Sandia Labs FY22 Laboratory Directed Research & Development Annual Report

DEVELOPMENT OF NOVEL LIQUID METAL SOLUTION CHEMISTRY PRODUCES RENEWABLE HYDROGEN BY WATER SPLITTING.

As an energy carrier, hydrogen (H 2 ) can be utilized as a domestic source of fuel, energy storage, and process heat. H 2 is sourced mainly by reforming hydrocarbons, which emits CO 2 . Renewable pathways to H 2 are expensive and/or inefficient, so the goal of this LDRD project was to formulate a liquid metal solution (LMS) that could be integrated into a hybrid thermochemical electrochemical process that utilizes heat and electricity from solar or

application is in prosecution, and follow-on funding was received through the DOE Solar Energies Technologies Office. Matthew Witman, a postdoc who contributed to the project and was later promoted to Sandia staff, was the co-winner of a 2021 Hydrogen Fuel Cell Technologies Office Postdoctoral Recognition Award. (PI: Andrea Ambrosini)

nuclear power to renewably produce H 2 via water-splitting (WS). The Sandia team developed an ML algorithm to predict candidate LMSs, fabricated a novel flow reactor to characterize the LMS reaction, and demonstrated H 2 production via WS in a molten Sn-Zn alloy at temperatures below 500°C. This process demonstrates novel, carbon-free H 2 production adoptable by the nuclear and solar industries and will advance the nation toward DOE Earth shot Hydrogen 1-1-1 goal ($1/1 kg/1 decade). To date, two Technical Advances were generated, a non-provisional patent

Schematic of the liquid metal solutions approach for the combined thermochemical and electrochemical water splitting.

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LABORATORY DIRECTED RESEARCH & DEVELOPMENT