Hydrodeoxygenation of Anisole by Using a Ruthenium-Containing Nickel-Iron Hydrotalcite-Based Catalyst

Abstract

Ruthenium-loaded nickel-iron (Ni−Fe) hydrotalcite materials were synthesized via the co-precipitation method. The physicochemical properties of the synthesized materials were characterized by spectroscopic and analytical methods. The highly crystalline nature of Ni−Fe HT (NiFe-0.5) hydrotalcite material was evident from powder XRD studies. The presence of uniformly dispersed ruthenium in its NiRu alloy form was evident from the TPR studies. The synthesized materials show promising catalytic performance for the hydrodeoxygenation (HDO) of anisole under ambient reaction conditions (190 °C, 20 bar H2). The catalyst prepared with a nickel-to-iron molar ratio of 2 : 1 (NF0.5 A) exhibited a good hydrotalcite structure and moderate catalytic activity for the hydrotreatment of anisole. The catalytic activity was improved by the introduction of 4 wt. % ruthenium on the surface of Ni−Fe hydrotalcite (NF0.5Ru), which shows 98 % anisole conversion with the selective formation of toluene as the major product. Catalytic activity remained for several consecutive runs. The recycled catalyst showed a similar conversion with the formation of toluene and methylcyclohexane as the major products. The variation in the selectivity might be due to the re-dispersion of Ni−Ru active sites.