Brönsted and Lewis acid ZSM-5 zeolites for the catalytic dehydration of glucose into 5-hydroxymethylfurfural

Aqueous‐Phase Transformation of Glucose into Hydroxymethylfurfural and Levulinic Acid by Combining Homogeneous and Heterogeneous Catalysis

“…[17] However,the subsequent reactions from fructosea re catalyzed by Brønsted acids. According to prior reports, Lewis acidity from solid catalysts is required to promote the glucose isomerization to fructose.…”

“…According to prior reports, Lewis acidity from solid catalysts is required to promote the glucose isomerization to fructose. [17] However,the subsequent reactions from fructosea re catalyzed by Brønsted acids. [17] The presence of am ineral acid promotes them, displacing the first equilibrium, as well as the Brønsted acid of thesez eolites.…”

“…[7,8] With this premise, the main limitingf actor is the good dispositiono fa cid sites:B rønsted acid catalysts, such as HCl, are required to promote dehydration and rehydration steps, whereas Lewis acids are neededt oc atalyze the isomerization from glucoset of ructose. [17] These sites are present in heterogeneous catalysts (zeolites, silico-aluminophosphate, Al-MCM-41, and Al-MSU-F mesoporous materials and zirconia). The activity of these types of materials was previously reported, with promising productivities to HMF and levulinica cid obtained.…”

Development of Betaine‐Based Sustainable Catalysts for Green Conversion of Carbohydrates and Biomass into 5‐Hydroxymethylfurfural

“…Therefore, the production of HMF from glucose was investigated. The formation of HMF from glucose involves two steps, the isomerization of glucose to fructose and the dehydration of glucose and fructose to HMF, which requires the presence of both Lewis and Bronsted acid sites . Therefore, we sought to convert glucose to HMF by combining BX and Lewis acid metal chlorides (MCl x :CuCl 2 ⋅2 H 2 O, FeCl 3 ⋅6 H 2 O, MgCl 2 ⋅6 H 2 O, SnCl 4 ⋅5 H 2 O, AlCl 3 ⋅6 H 2 O, NiCl 2 ⋅6 H 2 O, LaCl 3 ⋅ n H 2 O, CaCl 2 ⋅2 H 2 O, MnCl 2 ⋅4 H 2 O, CoCl 2 ⋅6 H 2 O).The carboxyl groups of BX are typical Bronsted acid, which can promote the dehydration of fructose to HMF or the rehydration of HMF to LA .…”

“…The formation of HMF from glucose involves two steps, the isomerization of glucoset of ructose and the dehydration of glucose and fructose to HMF,w hich requires the presence of both Lewis and Bronsted acid sites. [19] [20] Herein, B-Cl was investigated as ar epresentative BX because it can be obtained directly from beet. In the absence of aL ewis acid, the HMF yield was only 3% ( Other BX derivatives were also investigated for the dehydration of glucose in the presence of AlCl 3 .6H 2 O( Ta ble 4);l arge differences in activity were observed.…”