Selective switching hydrogenation products of 5-hydroxymethylfurfural at high substrate concentrations by regulating Pd-MgO interactions

• Published in: Applied catalysis. B, Environmental Vol. 361; p. 124578
• Main Authors: Lv, Mingxin, Huai, Liyuan, Chen, Guoxin, Zhao, Xi, Chen, Chunlin, Zhou, Shenghu, Zhang, Jian
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2025
• Subjects: 5-hydroxymethylfurfural; Biomass; Charge transfer; Interface; Selective hydrogenation; Selective hydrogenation; Biomass; Charge transfer; Interface; 5-hydroxymethylfurfural
• ISSN: 0926-3373
• DOI: 10.1016/j.apcatb.2024.124578

Controlling the selective activation of one or some functional groups as desired is still a challenge in hydrogenation, especially at high substrate concentrations. Herein, Pd-MgO interfaces over Al2O3 were finely regulated for efficiently selective hydrogenation of furan ring in 5-hydroxymethylfurfural (HMF) to produce 5-hydroxymethyltetrahydro-2-furaldehyde (5-HMTHFF) or total hydrogenation to 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF), also inhibiting side reaction. The Pd-MgO/Al2O3 with 12.0 wt% of MgO selectively hydrogenates the furan rings with a 5-HMTHFF yield of 82.4 % while that with 2.0 wt% of MgO totally hydrogenates HMF with a DHMTHF yield of 96.2 % at high substrate concentrations (400 mM). Characterizations and DFT calculations demonstrated that oligomeric MgO species suppress the agglomeration of Pd nanoparticles and strengthen HMF adsorption, consequently promoting total hydrogenation. Furthermore, Pdδ+-MgO1-x sites between the crystallized MgO and Pd metal favored tilted adsorption on the interface and weakened the activation of the CO bond, consequently selectively producing 5-HMTHFF. [Display omitted] •Selectivity switching hydrogenation products of 5-hydroxymethylfurfural.•Preferential activation of the furan ring in the HMF molecule.•Constructing close contact Pd-MgO interfaces over Al2O3.•A charge-separated metal-couple-site (Pdδ+-MgO1-x) over Pd-MgO/Al2O3.