Fatemeh Khosravitabar

1 INTRODUCTION Hydrogen gas (H₂) serves as a clean energy carrier, emitting no carbon dioxide (CO2) during combustion. Despite this potential, nearly all industrial H₂ production—about 95%—currently relies on fossil fuels, primarily via natural gas in steam methane reforming, which emits large quantities of CO₂ (Cavaliere 2022). Achieving climate neutrality requires a transition to zero carbon-emission technologies for H₂ production, known as green H₂.

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