Continuous Furfural Hydrogenolysis into 2-Methylfuran and 2-Methyltetrahydrofuran over Cu/γ–Al<sub>2</sub>O<sub>3</sub> with ReO<sub><i>x</i></sub> and WO<sub><i>x</i></sub> as Catalyst Boosters
Munsuree Kalong, Wanichaya Praikaew, Sakhon Ratchahat, Weerawut Chaiwat, Wanida Koo-amornpattana, Wantana Klysubun, Wanwisa Limphirat, Suttichai Assabumrungrat, Atthapon Srifa
Abstract
High Resolution Image Download MS PowerPoint Slide Cu/Al 2 O 3 catalysts, enhanced with ReO x and WO x as catalyst boosters, were employed for the hydrogenolysis of furfural (FAL) into 2-methylfuran (2-MF) and 2-methyltetrahydrofuran (2-MTHF) within a continuous fixed-bed reactor. Comprehensive catalyst analyses revealed that the addition of ReO x and WO x onto Cu/Al 2 O 3 catalysts resulted in reinforced metal–support interactions, while the acidity, in terms of both its strength and quantity, was influenced by these booster additions. Additionally, structural characterizations after H 2 reduction via X-ray diffraction, X-ray absorption near-edge structure, and X-ray photoelectron spectroscopy confirmed the coexistence of Cu in the forms of Cu 0 /CuO x across all of the Cu-containing catalysts, whereas the valence states of Re 0 /ReO x and WO x were detected for the ReCuAl and WCuAl catalysts, respectively. Operating at a maximum temperature of 220 °C, the ReCuAl catalyst achieved the highest combined yields of 2-MF and 2-MTHF at 80.4%, with the WCuAl catalyst reaching 89.0%, in contrast to the lowest yields of 54.0% obtained with the CuAl catalyst. These results underscore the positive impact of ReO x and WO x additions on Cu/Al 2 O 3 catalysts, in which the catalyst acidity, metal–support interactions, and coexistence of metallic and oxophilic sites influenced the hydrogenolysis process, leading to the enhanced production of 2-MF and 2-MTHF simultaneously from FAL.