Catalysis of ordered nanoporous materials for fructose dehydration through difructose anhydride intermediate

Advances in porous and nanoscale catalysts for viable biomass conversion

“…76 For fructose dehydration, narrow pore zeolites exhibited superior HMF selectivity (about 90%) at 85-94% fructose conversions (entry 4, Table 1), whereas larger pore zeolites promoted undesirable HMF oligomerization towards humins production. 77 Owing to strong acid properties, HY zeolite was found to be active for fructose-to-HMF transformation. 78 The subsequent hydrogenation of HMF to 2,5-dihydroxymethylfuran or 2,5-dimethylfuran was performed using a Cu/ZnO/Al 2 O 3 catalyst.…”

“…179 Many efforts have been undertaken to develop efficient sulfated mesoporous silica catalysts for the production of various bio-based chemicals, including 5-hydroxymethylfurfural (HMF). For instance, Cheng et al 77 revealed the beneficial role of a sulfated mesoporous silica, synthesized by impregnation of H 2 SO 4 on MCM-41, followed by calcination at 550 1C, for the dehydration of fructose to HMF. Owing to well-balanced pore size and acidity, the sulfated mesoporous silica afforded about 90% HMF selectivity at 94% fructose conversion (entry 9, Table 1).…”

Controlling the Reaction Networks for Efficient Conversion of Glucose into 5‐Hydroxymethylfurfural

“…Based on the knowledge of reaction network of hexose‐to‐HMF dehydration, optimum design of functionalized catalytic materials have been achieved. For example, some sulfonated‐ordered MCM‐41 or disordered mesoporous silica catalysts with weaker acidity strength and appropriate pore size have been prepared by Tsai group for converting fructose (11.5 wt %) into HMF. A fructose conversion of 94 % with a HMF selectivity of 88 % have been achieved over the sulfonated MCM‐41 catalyst in a biphasic MIBK/H 2 O solvent by virtue of the low acidity and mesoporous pore size that facilitate the diffusion of HMF and suppress formations of LA, FA, and humins from secondary reactions of HMF .…”

“…A fructose conversion of 94 % with a HMF selectivity of 88 % have been achieved over the sulfonated MCM‐41 catalyst in a biphasic MIBK/H 2 O solvent by virtue of the low acidity and mesoporous pore size that facilitate the diffusion of HMF and suppress formations of LA, FA, and humins from secondary reactions of HMF . Narrow pore zeolites (i. e., ZSM‐5, mordenite, and ZSM‐12) and sulfated mesoporous silica lead to a high HMF selectivity of 90 % with HMF yields at 76–85 %, whereas the large pore zeolite (i. e., 12‐MR) exhibits a low HMF selectivity with excessive formation of humins due to the shape selective catalysis for HMF oligomerization . Therefore, optimum design of functionalized catalytic materials based on the knowledge of reaction network leads to a simple practice but efficient catalyst for HMF synthesis.…”

Solvent Effects on Degradative Condensation Side Reactions of Fructose in Its Initial Conversion to 5‐Hydroxymethylfurfural

“…Notably, no signals assigned to the products from the degradative condensation of fructose were observed in DMSO (Figure f). Instead, the appearance of signals corresponding to [2 Fru‐ n H 2 O+Na] + ( n =1–6) species supported the mechanism of difructose anhydride (DFA)‐mediated fructose‐to‐HMF dehydration in DMSO because of the highly stable existence of caramel‐like [2 Fru–2 H 2 O+Na] + ( m / z 347) species . However, it is interesting to note that the [2 Fru–H 2 O+Na] + ( m / z 365) species was found to be the main DFA species in DIO, THF, GVL, and NMP.…”