The use of Pd catalysts on carbon-based structured materials for the catalytic hydrogenation of bromates in different types of water

[Display omitted] •Pd/carbon-based materials show high catalytic activity for the bromates removal.•Bromates conversion is favored with mesoporous supports.•Catalysts are active in a continuous system with natural and industrial wastewater.•Bromates conversion decreases in the same ratio as the H2 partial pressure. The aim of this work is to study the activity of new Pd catalysts, supported on two different nano structured carbon materials, for bromate catalytic hydrogenation. The influence of the support has been studied, obtaining the best results with a palladium catalyst supported on carbon nanofibers (CNF) grown in sintered metal fibers (SMF). The results have shown the importance of the catalyst support in order to minimize the mass-transfer limitations ensuring an efficient catalyst use. In this way the most active catalysts are those with a mesoporous structure containing high dispersed Pd nanoparticles. The activity of this catalyst for bromate reduction has been tested in different types of water, namely, distilled water, natural water and industrial wastewater. It has been shown that the catalyst activity depends on the water matrix and bromate reduction rate depends on the hydrogen partial pressure. The potential use of the catalyst has been studied in a continuous reactor. It has been observed that the catalyst is active without any important deactivation at least during 100h of reaction, but is necessary to avoid salt precipitation and plugging problems.