Cellobiose hydrolysis using acid-functionalized nanoparticles

Abstract

Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote its conversion to ethanol; however, substantial capital investment is required to enable separation of the acid, and corrosion-resistant materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange titration measurements yielded 0.9, 1.7, and 0.2 mmol H + /g of catalyst for PFS, AS, and BCOOH nanoparticles, respectively. Elemental analysis results indicated that PFS and AS nanoparticles had 3.1 and 4.9% sulfur, respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles as the catalyst at 175°C for 1 h, which was significantly higher than the conversion for the control experiment (52%). AS nanoparticles retained more than 60% of their sulfonic acids groups after the first run, and 65 and 60% conversions were obtained for the second and third runs, respectively.

Hydrolysis of Oligosaccharides Over Solid Acid Catalysts: A Review

“…Their intrinsic acidity is not very interesting, but they can be modified by treatments involving sulfone or sultone compounds and then include sulfonic (ÀSO 3 H) groups. [41,58] Lai et al [58,59] improved the catalyst recovery by adding paramagnetic iron species on SBA-15-SO 3 H. This process was also applied to nanoparticles CoFe 2 O 4 -SiO 2 -SO 3 H for cellobiose hydrolysis, [60] with glucose yields reaching 50 % for a 80 % cellobiose conversion. Sulfonated silicas have been tested for the hydrolysis of several soluble disaccharides (Table 3, entries 5-12).…”

Propyl-Sulfonic Acid Functionalized Nanoparticles as Catalyst for Pretreatment of Corn Stover

“…Then the particles were stored in 100 mL of ethanol. Cobalt iron oxide nanoparticles were coated with silica using the procedures reported in the literature [13,17,21]. The dispersion of CoFe 2 O 4 in ethanol was sonicated for 1 h. About 15 ml of this solution were added to 550 ml blend isopropanol and water 9:1.…”

“…Acid functionalized silica materials have been used as catalyst of the α-1,4glycosidic bonds in sucrose and starch [15] and β-1,4glycosidic bonds in cellobiose [16]. Acid functionalized nanoparticles were previously used for the hydrolysis of cellobiose [17] and for the solubilization of hemicelluloses [18]. In this work, silica coated cobalt iron oxide nanoparticles functionalized with propyl-sulfonic acid groups were synthesized and used as catalyst for the pretreatment of corn stover.…”

Impacts of acidity and textural properties of oxidized carbon materials on their catalytic activity for hydrolysis of cellobiose

“…In the presence of a sulfonated chloromethyl polystyrene resin, hydrolysis of cellobiose was complete within 2e4 h at 100e120 C, but 250 mg catalyst was used converting 100 mg of substrate [12]. In the presence of sulfonated silica, hydrolysis of cellobiose proceeds much faster [15,16]. However, sulfonated mesoporous silica as catalyst underwent a significant loss of the specific surface area under reaction conditions [17].…”