Glucan Adsorption on Mesoporous Carbon Nanoparticles: Effect of Chain Length and Internal Surface

Applied Catalysis B: Environmental

2014

269

142

Conversion of biomass to renewable and valuable chemicals has attracted global interest in order to build up sustainable societies. Cellulose is the most abundant and non-food biomass; however, the low reactivity of cellulose has prevented its use in chemical industry except for the paper manufacturing. The heterogeneous catalysis for the conversion of cellulose has been expected to overcome this issue, because various types of heterogeneous catalysts can be designed and applied in a wide range of reaction conditions. Furthermore, solid catalysts are easily recovered and reused. In this review article, we show the present situation and perspective of heterogeneous catalysis for the transformation of cellulose into useful platform 2 chemicals.

Section: Hydrolytic Hydrogenation Of Cellulose To Sorbitolmentioning

confidence: 99%

Catalytic transformation of cellulose into platform chemicals

Yabushita

Applied Catalysis B: Environmental

2014

269

142

“…Chung, Katz, and co-workers reported that a mesoporous carbon with pore diameter of 3.2 nm adsorbed cello-oligosaccharides in a Langmuir manner. 53 The adsorption amount was as much as 667 mg g…”

Section: Adsorption Of Cellulosic Molecules On Carbonmentioning

confidence: 99%

“…61 It has been demonstrated that mesopores of carbon (3.2 nm) can accommodate large cellulose molecules but micropores of SiO 2 do not even when the highest degree of negative Gibbs energy change of covalent bonding (substitution of SiCl with SiOcellulose) is available. 50a, 53 We used a zeolite-templated carbon (ZTC) 62 possessing homogeneous micropores with 1.01.5 nm diameters. ZTC was added to an HCl solution of long-chain cellulose molecules (molecular weight = 3600), which resulted in up to 800 mg g ¹1 of uptake.…”

Section: ¹1mentioning

confidence: 99%

Development of Solid Catalyst–Solid Substrate Reactions for Efficient Utilization of Biomass

Bulletin of the Chemical Society of Japan

2017

The efficient catalytic conversion of lignocellulose is a formidable issue, but it is worth studying in terms of the high potential as renewable chemical feedstock. In this account, we describe our approach to convert solid cellulose with solid catalysts. We found that carbons bearing weak acid sites were active for the hydrolysis of cellulose. The catalyst produced glucose in up to 88% yield after the formation of good solid solid contact, due to selective enhancement of the solidsolid interfacial reaction. We also developed a cyclic system to efficiently convert real lignocellulosic biomass. Mechanistic study has revealed that polycyclic carbon aromatics attract cellulose by CHπ interactions mainly consisting of dispersion forces and hydrophobic interactions. The adsorbed cellulose molecules diffuse on the surface, rapidly penetrate even micropores, and undergo hydrolysis by weak acid sites such as carboxylic acids. Phenolic or carboxylic groups adjacent to the weak acid increase the frequency factor by forming hydrogen bonds. The combined functions of carbon derived from both polar and nonpolar groups achieve the hydrolysis of cellulose. Finally, we comment on future perspective to apply these findings.

“…The yield of glucose strongly depended on types of carbon catalyst used. It is notable that the graphitic surface of carbon also plays a role in adsorbing the cellulosic molecules by van der Waals force, CH _ π hydrogen bonding, and hydrophobic interaction 22), 23) . Hence, both hydrophilic and hydrophobic groups on carbon are essential for superior performance of the catalyst.…”

Section: Conversion Of Cellulose By Heterogeneousmentioning

confidence: 99%

機械的処理によるセルロースから基盤化学品への効率的な触媒分解

Shrotri

2015

J. Jpn. Petrol. Inst.

Mechanical treatment of cellulose is an emerging concept for dramatically increasing the hydrolytic reactivity of cellulose. We report here the recent developments in the field of mix-milling and mechanocatalysis for cellulose pre-treatment. Mix-milling enhances the solid-solid contact between cellulose and carbon catalyst during hydrolysis reaction. Kinetic study shows that mix-milling specifically enhances the rate of cellulose to oligomer hydrolysis (13 fold), whereas the rate of oligomer to glucose hydrolysis is not influenced. Very high glucose yield of 88 % was obtained by mix-milling cellulose with K26 and using trace amount of HCl. Mix-milling was also applicable for single-pot hydrolytic hydrogenation of cellulose to sugar alcohols. Ru/AC catalyst was stable under mix-milling condition and 68 % of sugar alcohol was obtained using only 9 atm H2 pressure. Unlike mixmilling, mechanocatalysis takes advantage of presence of strong acid catalyst during milling to depolymerize cellulose. Completely soluble glucans were obtained after 7.5 h of milling in the presence of 0.25 mmol of acid g -1 cellulose. The glucans were highly reactive towards conventional and transfer hydrogenation reaction, affording ca. 90 % sugar alcohol yield in both cases after 1 h reaction. The transfer hydrogenation of cellulosic glucans was successfully upgraded to a lab-scale fixed-bed reactor.