How Trace Impurities Can Strongly Affect the Hydroconversion of Biobased 5-Hydroxymethylfurfural?

Abstract

Selective conversion of 5-hydroxymethylfurfural (HMF) to liquid fuels is an important step in the valorization of carbohydrates. Although not paid much attention to in the scientific community, we discovered an enormous impact of the HMF purity on the product selectivity during its hydroconversion in the presence of Ru/C. The presence of dimethyl sulfoxide (DMSO) showed the most dramatic effect on the aromatic hydrogenation activity, with almost full selectivity for either 2,5dimethylfuran (DMF) or 2,5-dimethyltetrahydrofuran (DMTHF). The sulfur to surface ruthenium molar ratio predicts the selectivity outcome. A similar selective poisoning effect of DMSO was observed while using 2,5-bis(hydroxymethyl)furan (BHMF) as feedstock. These findings provide an approach to modify the selectivity of HMF conversion using the Ru/C catalyst and draw attention to the utmost importance of biobased reagent purity for catalytic studies to avoid erroneous conclusions about catalyst properties.

Iodine‐Modified Pd Catalysts Promote the Bifunctional Catalytic Synthesis of 2,5‐Hexanedione from C6 Furan Aldehydes

“…Transition metal/acid supports are widely used as heterogeneous catalysts in various tandem reactions including hydrogenation catalysis and acid catalysis in the modern chemical industry. [1][2][3][4] To decrease the carbon footprint and develop a sustainable economy, these catalysts have attracted widespread interest for use in the upgrading of unsaturated biomassderived C 6 furfurals (5-methylfurfural, 5-hydroxymethylfurfural) to valuable chemicals, such as hydrogenative etherification to furan ethers (2-alkoxymethyl-5-methylfuran, 2,5-bisalkoxymethylfuran), [5][6][7] hydrogenative ring-rearrangement to cyclic ketones (3-methylcyclopentanone, 3-hydroxymethylcyclopentanone), [8][9][10][11][12][13] hydrogenative hydrogenolysis to 2,5dimethylfuran and 2,5-dimethyl tetrahydrofuran, [14][15][16] hydrogenative ring-opening to linear ketones (1-hydroxyl-2,5-hexanedione, 2,5-hexanedione). [17][18][19] Among these compounds, 2,5-hexanedione (HD) is an important high-value commodity chemical for performing various upgrades to solvents, polymers, fragrances, and drugs.…”

Catalytic Hydroconversion of 5‐HMF to Value‐Added Chemicals: Insights into the Role of Catalyst Properties and Feedstock Purity

“…Interesting results, for instance, were obtained while optimizing HMF conversion to DMTHF using Ru/C catalyst. [70] A dual catalytic behavior was found during the screening of various high purity HMF feedstocks (> 97 %) from commercial suppliers. The key reaction product was either DMTHF with a yield of > 70 % or DMF with a yield of > 90 %.…”

“…[91] The commercial sample supplied by Sigma Aldrich contained 0.5 wt% of DMSO, which is consistent with a previously discussed report. [70] Authors decided to dope the reaction feed with additional DMSO, while using 15 wt% Ni/SiO 2 catalyst. While no shift in selectivity was discussed, the recent results, similarly as with Ru/C, indicate a rate deactivation effect of DMSO when its concentration increased from 0.5 to 8.5 wt%.…”

Sustainable Catalytic Transformation of Biomass‐Derived 5‐Hydroxymethylfurfural to 2,5‐Bis(hydroxymethyl)tetrahydrofuran

“…Turkin et al showed that a sudden and considerable product selectivity shift from DMTHF to 2,5-DMF in the Ru/C-catalyzed hydroconversion of 5-HMF was triggered by the presence of incompletely removed DMSO found in different commercial HMF feedstocks. [81] Therefore, it is highly desired to integrate catalytic steps in which the 5-HMF intermediate generated from raw biomass is directly subjected to the next transformations (oxidation, hydrogenation, oxidative esterification, etc.) to provide valuable products in one-pot fashion.…”