Hydrodeoxygenation of Guaiacol to Cyclohexanol Using Noble Metal‐Supported Ni‐Based Perovskite‐Derived Catalysts

Abstract This study focuses on the role of noble metal‐doped Ni‐based perovskites, specifically LaNiO 3 and NiTiO 3 catalysts in the hydrodeoxygenation (HDO) of guaiacol. The findings demonstrate that reduced Ru‐LaNiO 3 catalyst achieved superior performance with 100% guaiacol conversion and a 75% selectivity toward cyclohexanol, compared to reduced Ru‐NiTiO 3 , which achieved only 43% conversion and 25% cyclohexanol selectivity under identical conditions (240 °C, 30 bar H 2 , and 4 h). High‐resolution transmission electron microscopic (HR‐TEM) analysis reveals that LaNiO 3 ‐supported catalysts exhibit better metal dispersion and smaller nickel nanoparticle sizes compared to NiTiO 3 ‐supported counterparts. X‐ray photoelectron spectroscopy (XPS) analysis shows that the reduction of nickel and noble metals is more facile on LaNiO 3 . Additionally, the O 1s XPS profile for reduced Ru‐LaNiO 3 indicates a higher proportion of lattice oxygen (O Lat ∼ 79%) and a lower proportion of oxygen vacancies (O Vac ∼ 21%) compared to other catalyst systems. The optimized O Lat /O Vac 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‐LaNiO 3 than reduced Ru‐NiTiO 3 , 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.