Hydrogen has the potential to act as a superior energy carrier when compared to fossil fuels, as it has approximately twice the gravimetric energy density and could have none of the carbon emissions. However, the primary mode of producing hydrogen today is from reforming of fossil fuels (natural gas, oil, and coal), which together account for 96% of production. This is hardly a solution for enabling sustainable energy. Additionally, as of 2020 most (>98%) hydrogen is produced for chemical, nonenergetic purposes such as ammonia production and oil refinement. It is well known that industrial ammonia production is central to sustaining the Earth's human carrying capacity; this underscores the importance of developing renewable hydrogen production avenues. In this paper, we refer to the integration of renewable hydrogen into the global energy system as the green hydrogen economy (GHE) and explore research trends in each of the three facets of the green hydrogen economy: green hydrogen production, hydrogen storage, and hydrogen-based fuel cells. Using data from the CAS Content Collection™, we analyze the academic and patent literature from 2011-2021 to understand the general progress of each field as well as the classes of materials and concepts driving their innovation. As an expert-curated resource, CAS content is utilized here for quantitative analysis of publications against variables including time, country/region, research area, and substance details. We hope that this manuscript serves as a broad overview of the materials research directions driving the potentially transformative set of GHE technologies.