Heteroatom-doped carbon nanomaterials as potential heterogeneous Fenton reaction catalysts

Abstract

Designing efficient, abundant, and durable catalysts for the heterogeneous Fenton reaction is essential for the development of novel advanced oxygenated systems. The high complexity of the reaction mechanism and catalyst structure makes the rational fabrication of heterogeneous Fenton catalysts a grand challenge. This work presents a systematic investigation of the catalytic activity, including its intrinsic relation with the structural characteristics, of hydrogen peroxide (H₂O₂) dissociation on heteroatom-doped carbon nanomaterials. A volcano relationship between the catalytic activity and the adsorption energies of reaction intermediates was found for the H₂O₂ dissociation on heteroatom-doped graphene, while nearly linear relationships were formed on heteroatom-doped carbon nanotubes (CNTs) and nanoribbons. The curvature of CNT walls enhances the adsorption of reaction intermediates, which accelerates the initial dissociation of H₂O₂ molecules but hampers the formation of the final products (or the release of the final products). Boron-doped graphene and nitrogen-doped CNTs, which balance the activation energies of initial H₂O₂ dissociation and the removal of oxygen-containing species, exhibit excellent activity for the catalytic cycle. This work provides a mechanistic insight into the structure–activity relationships in the catalytic dissociation of H₂O₂ and can potentially contribute to advancing the rational development of heterogeneous catalysts for wastewater treatment.