(Invited) The U.S. Department of Energy’s Hydrogen Consortium for Advanced Water Splitting Materials

The goals of the Hydrogen and Fuel Cell Technologies Office (HFTO) support those of the Biden Administration to build a clean and equitable energy economy and address the climate crisis through development and deployment of hydrogen technologies to the benefit of all Americans. HFTO is dedicated to meeting the goals of DOE’s Hydrogen Shot, 1 which targets affordable clean hydrogen production at $1/kg within the decade, and the H2@Scale Initiative, 2 which aims to advance affordable hydrogen to enable decarbonization and revenue opportunities across multiple sectors. HFTO’s HydroGEN consortium (https://www.h2awsm.org) for advanced water splitting (AWS) materials, part of the DOE’s Energy Materials Network (EMN), focuses on multiple clean hydrogen production pathways, including several relevant to renewable fuels via artificial photosynthesis. Since the consortium’s establishment in 2016, HydroGEN researchers have made significant progress in the areas of low and high temperature electrolysis, as well as solar thermochemical (STCH), and most relevant here, photoelectrochemical (PEC) hydrogen production pathways. The HydroGEN consortium facilitates collaborations between national laboratories, academia, and industry, bringing together world-class technical expertise with state-of-the-art facilities made available to project partners. HydroGEN offers an extensive collection of materials research capabilities for addressing R&D challenges. Project participants can choose from over 40 unique capability nodes. Each capability node is comprised of a combination of a tool, technique, and expertise that is unique to the national laboratory system. HydroGEN has supported over 30 competitively selected R&D projects with industry and academic partners by providing streamlined access to national lab resources and expertise. The consortium is also involved in fostering cross-cutting activities to advance material performance and durability through community engagement and protocol development and initiating critical laboratory-led efforts to address specific R&D gaps in the AWS portfolio. A new cohort of solar fuels focused projects were recently selected through the Funding Opportunity Announcement (FOA) Number: DE-FOA-0002792 with additional funding in this area expected in the future. A total of 11 new projects were selected, six in PEC and five in STCH, to work with the HydroGEN consortium towards advancing solar fuels production technology. Projects from both technology pathways must define materials metrics and targets for meeting the interim hydrogen cost target of $2/kg-H 2 with extrapolation to additional requirements for meeting $1/kg-H 2 . Selected PEC projects focused on the development of materials or material systems for efficient and durable PEC water-splitting with a focus on innovations in bandgap and bandgap alignment, functional interfaces, stable surface catalysis, and protective coatings. A successful PEC photoelectrode project will need to achieve 15% STH efficiency for the entirety of operation exceeding 1,000 hours, with proposed pathways for achieving efficiencies up to 25% and durability up to 10,000 hours. Further, PEC systems will be required to demonstrate hydrogen production at a rate of 0.1 g/h for diurnal operation over two weeks. Selected STCH projects focused on accelerating discovery, development, and demonstration of alternative redox materials for a two-step STCH process and addressing projected costs and materials challenges associated with the required operating temperatures. Successful STCH projects will need to include a demonstration of the STCH process using sunlight or simulated sunlight. STCH systems must demonstrate hydrogen production at a rate of 1 g/h for diurnal operation over two weeks. For the first time, in line with the Justice40 Initiative, 3 applicants were required to submit DEIA (diversity equity, inclusion, and accessibility) plans. Objectives from these plans were incorporated into the project objectives with specific goals identified for each year. Despite the progress, there is still significant ground to be covered through water splitting materials R&D. With the support of HydroGEN, these selected projects will help to address remaining challenges and enable low-cost and large-scale hydrogen production. An overview of consortium and project goals and objectives will be discussed. Hydrogen Shot | Department of Energy H2@Scale | Department of Energy, The Justice40 initiative, created by Executive Order 14008, establishes a goal that 40% of the overall benefits of certain federal investments flow to disadvantaged communities. Figure 1