Steam reforming of phenol toward cleaner hydrogen production over bimetallic Ni/Ti modified zinc titanate perovskite in tandem with a kinetic model development

Hydrogen as a clean energy carrier with high heat combustion and zero environmental impacts is an attractive alternative to fossil fuels. In this study, NiO/TiO₂ modified ZnTiO₃ perovskite (NTZ) with high reducibility catalyst was designated by co-precipitation method and examined in the reaction of steam reforming of phenol (SRP) for H₂ production. The activity tests for SRP were carried out in a fixed bed reactor (FBR) under different operating conditions. The NTZ-composite consisting of NiO/TiO₂ loaded ZnTiO₃ perovskite achieved the highest yield of H₂ and phenol conversion of ~76 and 90%, respectively, with excellent durability and time on stream (50 h) stability without obvious deactivation. The high exposed active sites of NiO/TiO₂ metals over the bi-metal support (ZnTiO₃) and the metal-support interaction significantly improved the catalytic performance. The products distribution of H₂, CO₂, and CO as a measure of the dominant reactions; SRP, water gas shift (WGS), and reverse water gas shift (RWGS) were correlated to kinetic models and developed according to Langmuir-Hinshelwood-Hougen-Watson (LHHW) expressions. LHHW model accurately fitting the experimental results with surface reactions as the kinetic limitations. SRP reaction revealed the highest rate constant of 21.70 mol g-cat⁻¹ h⁻¹ atm⁻¹ with 39.96 kJ mol^-1 activation energy. NTZ is a promising catalyst for the SRP reaction toward H₂ production with minimum kinetic limitations and would be promising in the clean energy production and other environmental applications.