This study focuses on the role of noble metal-doped Ni-based perovskites, specifically LaNiO3 and NiTiO3 catalysts in the hydrodeoxygenation (HDO) of guaiacol. The findings demonstrate that reduced Ru-LaNiO3 catalyst achieved superior performance with 100% guaiacol conversion and a 75% selectivity toward cyclohexanol, compared to reduced Ru-NiTiO3, which achieved only 43% conversion and 25% cyclohexanol selectivity under identical conditions (240 degrees C, 30 bar H2, and 4 h). High-resolution transmission electron microscopic (HR-TEM) analysis reveals that LaNiO3-supported catalysts exhibit better metal dispersion and smaller nickel nanoparticle sizes compared to NiTiO3-supported counterparts. X-ray photoelectron spectroscopy (XPS) analysis shows that the reduction of nickel and noble metals is more facile on LaNiO3. Additionally, the O 1s XPS profile for reduced Ru-LaNiO3 indicates a higher proportion of lattice oxygen (OLat similar to 79%) and a lower proportion of oxygen vacancies (OVac similar to 21%) compared to other catalyst systems. The optimized OLat/OVac ratio is shown to be critical for the effective HDO of guaiacol. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrates a high HDO reaction rate using reduced Ru-LaNiO3 than reduced Ru-NiTiO3, with cyclohexanol formation attributed to the keto-enol tautomerization pathway. Overall, this study underscores the critical roles of oxygen vacancies, metal dispersion, and metal-metal oxide interactions in the HDO of guaiacol.

Foreign