Protonated titanate nanotubes as a highly active catalyst for the synthesis of renewable diesel and jet fuel range alkanes

Abstract

Protonated titanate nanotube (PTNT) was first reported as a good catalyst for the hydroxyalkylation/alkylation (HAA) of 2-methylfuran (2-MF) and n-butanal from lignocellulose. Compared with other inorganic solid acids, PTNT has higher catalytic activity and efficiency. Over it, high yield of HAA product (77%) was achieved under mild reaction conditions. PTNT is also effective for the HAA (or alkylation) reactions between 2-MF and other lignocellulosic carbonyl compounds. According to the characterization results, the hydrothermal treatment of TiO2 P25 with NaOH solution and subsequent acidification significantly increases its BET surface area and the amount of acid sites on the surface of catalyst. Moreover, these pretreatments also lead to the generation of strong acid sites and Brönsted acid sites on the surface of catalyst. All of these changes are responsible for the excellent performance of PTNT. As the final aim of this work, the HAA product of 2-MF and n-butanal was converted to diesel and jet fuel range brached alkanes by the hydrodeoxygenation (HDO) over zeolite loaded Ni catalysts. Among them, Ni/H-ZSM-5 demonstrated the best catalytic performance and good stability, which makes it a promising catalyst in future application.