Hydrogen production is the foundational process for the emerging clean energy economy, yet the methods used to generate this gas vary wildly in their environmental impact, cost, and scalability. At its simplest, hydrogen production involves separating H2 molecules from other elements, but the source of that separation defines the final product's "color." The vast majority of todays supply comes from steam methane reforming (SMR), a process that mixes methane with high-temperature steam to produce hydrogen and carbon dioxide. This is called fossil-based H2, and while it is cheap and well-established, it generates roughly significant greenhouse gas emissions. Companies like a German industrial giant and Air Products have perfected SMR at a massive scale, operating hundreds of SMR facilities across the Gulf Coast and Europe. However, the push to decarbonize has led these same firms to invest heavily in CO2 sequestration technology, converting gray hydrogen production methods into blue hydrogen.