The promotional effect of surface Ru decoration on the catalytic performance of Co-based nanocatalysts for guaiacol hydrodeoxygenation

Abstract

In the present work, carbon-supported Ru-decorated Co-based nanocatalysts were fabricated via a layered double hydroxide/carbon composite precursor approach and applied to the efficient hydrodeoxygenation (HDO) of guaiacol to produce cyclohexanol. It was demonstrated that uniform and highly dispersed Co nanoparticles could be formed on the carbon matrix, and the decoration of a small amount of Ru on the surface of Co nanoparticles could introduce stronger hydrogenolysis active sites. Furthermore, the reduction temperature for catalyst precursors could tune the size of Co-containing nanoparticles and regulate the density of surface oxygen vacancies originating from CoOx species. Under the mild reaction conditions (200 ℃ and 1.0 MPa hydrogen pressure), as-fabricated Ru-Co/C catalyst obtained at the reduction temperature of 600 °C showed excellent catalytic activity in the HDO of guaiacol, with a high cyclohexanol yield of ∼94 %, which was attributable to surface exposure of highly dispersive Ru° sites and the formation of abundant defective oxygen vacancies. The present results provide a new approach for designing high-performance Co-based HDO nanocatalysts by both the surface decoration of small amounts of precious metals and the introduction of surface defective structures.