Alternative H₂O₂ Production Processes: An Outlook on Candidate Technologies Beyond the Anthraquinone Process

Hydrogen peroxide is currently made on a large scale via the auto-oxidation (AO) process, an indirect process via the hydrogenation of anthraquinone over a Pd catalyst, followed by reaction with O₂. The AO process has a significant climate footprint, since H₂ is usually sourced from methane steam reforming. A more sustainable H₂O₂ production process is, therefore, highly relevant. Potential alternative routes include the direct reaction of H₂ and O₂ and processes that use electricity, either directly via electrochemical or bioelectrochemical systems or indirectly via plasmas. Despite research on these routes, there are currently no real challengers to the established AO process. An overview of these alternative processes is provided before considering the energetic, techno-economic, life cycle, and safety challenges facing them. By highlighting these challenges through comparison with the AO process, this review aims to inspire further work for scaling up these alternative processes for truly determining their industrial viability. As these processes may ultimately prove more advantageous than the AO process for on-demand production, their industrialization might not need to occur on the same production scale as that of the AO process.