The Effect of Gold Nanoparticles on the Catalytic Activity of NiTiO3 for Hydrodeoxygenation of Guaiacol

Guaiacol is a typical model compound used to investigate and understand the hydrodeoxygenation behaviour of bio-oils, which is critical to their application as an alternative to fossil resources. While extensive research has been carried out on developing catalysts for guaiacol hydrodeoxygenation, the true active sites in these catalysts are often illusive. This study investigated the effect of Au-loading on the catalytic activity of NiTiO3 for the hydrodeoxygenation of guaiacol. It showed that metallic Ni formed by the partial reduction in NiTiO3 was responsible for its catalytic activity. Au-loading in NiTiO3 effectively reduces the temperature required for the NiTiO3 reduction from 400 °C to 300 °C. Consequently, at an Au-loading of 0.86 wt%, the 0.86 Au/NiTiO3-300 °C catalyst was found to deliver a guaiacol conversion of ~32%, more than 6 times higher than that of the pure NiTiO3-300 °C catalyst.