The Use of H₂ in Catalytic Bromate Reduction by Nanoscale Heterogeneous Catalysts

The formation of bromate (BrO₃^-)in groundwater treatment is still a severe environmental problem. Catalytic hydrogenation by nanoscale heterogeneous catalysts with gaseous H₂ or solid-state H₂ has emerged as a promising approach, which relies on reducing BrO₃^- to innocuous Br^- via the process of direct electron transfer or reduction with atomic hydrogen. Several nanocatalysts have demonstrated high efficiency with a 100% effective BrO₃^- reduction with greater than 95% of Br^- generation in the batch and continuous reactors. However, this technology has not been widely adopted in water treatment systems. Indeed, this research article summarizes the advantages and disadvantages of these technologies by highlighting the factors of nanomaterials reduction efficiency, long-term durability, and stability, as well as addressing the essential challenges limiting the implementation of the use of H₂ for BrO₃^- reduction. In this work, we provide an economic evaluation of catalytic BrO₃^- removal, safe hydrogen supply, storage, and transportation.