Theoretical Insight into the Mechanism for the Cellobiose-to-Sorbitol Hydrogenation Over Diatomic Ru2/NC Catalyst
Ru/NC shows a good catalytic performance in cellobiose-to-sorbitol hydrogenation. However, the molecular origins of the selective orientation of the reaction pathway remain unclear. Here, we rationally designed the Ru2/NC catalyst, for which Ru2N8 V4 is preferred as the model. The hydrogenation mech...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1999. - 40(2024), 48 vom: 03. Dez., Seite 25670-25678 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Ru/NC shows a good catalytic performance in cellobiose-to-sorbitol hydrogenation. However, the molecular origins of the selective orientation of the reaction pathway remain unclear. Here, we rationally designed the Ru2/NC catalyst, for which Ru2N8 V4 is preferred as the model. The hydrogenation mechanisms for the hydrogenation of β-cellobiose to sorbitol employing H2 as the H-source in aqueous solution have been investigated over Ru2@N8 V4 at the GGA-PBE/DNP level. For the hydrogenation of β-cellobiose to sorbitol, the optimal reaction pathway involves the ring-opening of cellobiose with H2O as a promoter and then the hydroreduction of aldehyde group, followed by the β-1,4-glycosidic bond hydrolysis. The selective orientation of the optimal reaction pathway originates from the dissociation of H2O on Ru-sites of Ru2@N8 V4 to form Brønsted acid (Ru-H+) and Brønsted base (Ru-OH-), which collaboratively promote the ring-opening. The rate-determining steps are relative to the β-1,4-glycosidic bond cleavage, where an applicable π-π interaction between reactant molecule and Ru2@N8 V4 is of critical importance. Kinetically, the β-1,4-glycosidic bond cleavage from cellubitol is more favorable than that from β-cellobiose. For the hydrogenation of β-cellobiose to cellubitol, the first ring-opening with H2O as promoter and then hydrogenation are kinetically superior to the direct hydrogenation and ring opening. This derives from its dissociation over Ru-sites to Ru-H and Ru-OH groups. Predictably, protic solvents (HOR) are readily dissociated into Ru-H and Ru-OR at Ru-sites, which can promote the ring-opening of pyran-ring. The present research outcomes should contribute to the theoretical understanding necessary for the development of novel supported noble metal N-doped carbon catalysts for the hydrogenation of cellulose |
|---|---|
| Beschreibung: | Date Revised 03.12.2024 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.4c03636 |