This material is based upon work supported by the U.S. Depart-777 ment of Energy (DOE), Office of Energy Efficiency and Renewable 778 Energy (EERE), specifically the Hydrogen and Fuel Cell Technolo-779 gies Office. Sandia National Laboratories is a multi-mission lab-780 oratory managed and operated by National Technology and En-781 gineering Solutions of Sandia, LLC., a wholly owned subsidiary 782 of Honeywell International, Inc., for the U.