Tri-metallic Ni–Co modified reducible TiO2 nanocomposite for boosting H2 production through steam reforming of phenol

Abstract

Well-designed Co3O4 nanocubes (NCs) dispersed NiO/TiO2 to construct tri-metallic reducible NiO/TiO2/Co3O4 NCs structured catalyst for steam-reforming of phenol (SRP) with enhanced hydrogen production has been investigated. The controlled morphology with good dispersion was obtained, enabling efficient SRP toward selective H2 production. Using 10% NiO- 5% Co3O4 NCs/TiO2 composite, H2 yield of 69.91% and phenol conversion of 78.4% was achieved, significantly higher than using NiO/TiO2 and TiO2 samples. The cubical structured Co3O4 dispersed NiO/TiO2 composite showed significantly improved H2 yield and phenol conversion due to strong metal-support interaction with reducible support for providing more active sites. The H2 production was further increased by increasing reaction temperature, phenol concentration, feed flow rate and catalysts loading, however, they have adverse effect on the selectivity due to more CO formation. The composite catalyst possesses excellent activity and stability due to strong tri-metallic interaction and exceptional electronic interfaces. The spent catalyst analysis confirms the formation of graphene and carbon nanotubes over the reducible support. This study reveals that Co3O4 NCs are able to increase NiO/TiO2 activity for H2 production by inhibiting carbon monoxide formation and would be beneficial in other reforming applications.