Catalytic Transfer Hydrogenation and Acid Reactions of Furfural and 5-(Hydroxymethyl)furfural over Hf-TUD-1 Type Catalysts

authors	Antunes, MM; Silva, AF; Bernardino, CD; Fernandes, A; Ribeiro, F; Valente, AA
nationality	International
journal	MOLECULES
author keywords	heterogeneous catalysis; carbohydrate biomass; furfural; 5-(hydroxymethyl)furfural; furanic ethers; mesoporous silicates; TUD-1; hafnium
keywords	COUPLED TRANSFER HYDROGENATION; MEERWEIN-PONNDORF-VERLEY; ONE-POT CONVERSION; GAMMA-VALEROLACTONE; BETA-ZEOLITE; TRANSFER HYDROGENATION/HYDROGENOLYSIS; EFFICIENT CONVERSION; ALKYL LEVULINATE; ETHYL LEVULINATE; LEWIS
abstract	Heterogeneous catalysis, which has served well the petrochemical industry, may valuably contribute towards a bio-based economy by sustainably enabling selective reactions to renewable chemicals. Carbohydrate-containing matter may be obtained from various widespread sources and selectively converted to furanic platform chemicals: furfural (Fur) and 5-(hydroxymethyl)furfural (Hmf). Valuable bioproducts may be obtained from these aldehydes via catalytic transfer hydrogenation (CTH) using alcohols as H-donors under relatively moderate reaction conditions. Hafnium-containing TUD-1 type catalysts were the first of ordered mesoporous silicates explored for the conversion of Fur and Hmf via CTH/alcohol strategies. The materials promoted CTH and acid reactions leading to the furanic ethers. The bioproducts spectrum was broader for the reaction of Fur than of Hmf. A Fur reaction mechanism based on literature data was discussed and supported by kinetic modelling. The influence of the Hf loading and reaction conditions (catalyst load, type of alcohol H-donor, temperature, initial substrate concentration) on the reaction kinetics was studied. The reaction conditions were optimized to maximize the yields of 2-(alkoxymethyl)furan ethers formed from Fur; up to 63% yield was reached at 88% Fur conversion, 4 h/150 degrees C, using Hf-TUD-1(75), which was a stable catalyst. The Hf-TUD-1(x) catalysts promoted the selective conversion of Hmf to bis(2-alkoxymethyl)furan; e.g., 96% selectivity at 98% Hmf conversion, 3 h/170 degrees C for Hf-TUD-1(50).
publisher	MDPI
isbn	1420-3049
year published	2021
volume	26
issue	23
digital object identifier (doi)	10.3390/molecules26237203
web of science category	23
subject category	Biochemistry & Molecular Biology; Chemistry, Multidisciplinary
unique article identifier	WOS:000739652300001