Optimized Acidic Sites Distribution for Selective Synthesis of Alkylated Decalins over Acid-Treated Ru/HZSM-5

Producing high-density fuel of alkylated decalins from hydrodeoxygenation (HDO) of naphthalene derivatives is an environmentally friendly but still challenging method. Herein, a bifunctional Ru/HZSM-5 catalyst was fabricated by acid treatment (citric acid, oxalic acid, nitric acid) to effectively synthesize the alkylated decalins via HDO of naphthalene derivative. Acid treatment adjusted the acidic site distribution of Ru/HZSM-5. Nitric acid treatment (NA) resulted in more abundance of weak acidic sites which was beneficial for the dehydration process in HDO, and the lowest ratio of BAS/LAS to promote the hydrogenation of alkylated octalins, the rate-determining step of HDO. NA-treated Ru/HZSM-5 showed the highest HDO activity with the highest selectivity of 1,2-dimethyldecalin (74%). Besides, it also presents good HDO activity of naphthalene derivatives to produce high-density hydrocarbons. Therefore, Ru/HZ5-NA is a promising catalyst for the production of alkylated decalins and other high-value biofuels and chemicals.