Catalytic methane decomposition to boost the energy transition: Scientific and technological advancements

Decarbonization of the energy sector is a topic of paramount importance to avoid irreversible global warming. Hydrogen has been considered as the most suitable option to replace fossil fuels in industrial, residential and transport applications. However, hydrogen production has been almost limited to the reforming of hydrocarbons, which release large amounts of CO2, thus requiring several downstream purification processes. Catalytic methane decomposition consists of the low-temperature cracking of methane, producing only COx-free hydrogen and solid carbon. This process has the unique potential to make the swift transition for a fully decarbonized economy and beyond: the methane decomposition of biomethane removes CO2 from the atmosphere at competitive costs. Yet, industrialization of catalytic methane decomposition has been hindered by the insufficient stability assigned to catalyst deactivation due to carbon clogging. This article reviews not only the main accomplishments on methane decomposition since it was firstly reported, but also addresses technical barriers that have hindered its industrialization. Unlike other previous reviews that focused mainly on catalysts, more attention was put on the reactor design, catalyst regeneration strategies and processing of products (hydrogen purification and economic overview). The goal is to identify challenges and provide solutions for the industrialization paradigm that methane decomposition has faced up to now