Effects of Brønsted and Lewis acidities on activity and selectivity of heteropolyacid-based catalysts for hydrolysis of cellobiose and cellulose

Abstract

Heteropolyacids (H 3 PW 12 O 40 , H 4 SiW 12 O 40 ) and salts of metal cations (M n+ ) and PW 12 O 40 3-(M 3/n PW 12 O 40 ) act as effective homogeneous catalysts for selective hydrolysis of cellobiose and cellulose to glucose and total reducing sugars (TRS), respectively, in an aqueous phase. For Brønsted acid catalysts, including mineral acid and heteropolyacids, the activity for both reactions increases with a decrease in the deprotonation enthalpies (DPE), indicating that stronger Brønsted acidity is more favorable. For M 3/n PW 12 O 40 of 11 kinds of metal ions

Comparative study of different catalysts for the direct conversion of cellulose to sorbitol

“…Therefore, designing more efficient catalytic systems for the conversion of cellulose to platform chemicals is highly desirable. For the hydrolysis of cellulose strong mineral acids, such as hydrochloric acid or sulfuric acid, are traditionally used, but they are corrosive and have to be separated from the reaction mixture [1,5]. An ideal alternative is to use a heterogeneous catalyst, which is easily separable from the reaction mixture [2,10].…”

“…Cellulose, the most abundant source of biomass on Earth, is currently regarded as a promising alternative for the sustainable supply of fine chemicals and fuel, as it cannot be digested by humans and thus its use, unlike corn or starch, will not impose a negative impact on food supplies [4,5]. The development of an efficient and sustainable catalytic process for the conversion of cellulose into target products has been regarded as one viable way to reduce CO 2 emissions and alleviate the energy crisis, providing a long-term solution to the industrial dependence on fossil carbon [5]. One of the alternative is the one-pot hydrolytic hydrogenation of cellulose to sugar alcohols over bi-functional heterogeneous catalysts.…”

Hydrophobic Lurylamine Modified Heteropoly Acid as an Efficient and Recyclable Catalyst for the Hydrolysis Reaction in Aqueous Solution under Microwave

“…11 The effects of Bronsted and Lewis acidity on the activity and selectivity of the HPA-based catalyst for the hydrolysis of cellulose were also discussed in another reports. 12 HPAs together with supported ruthenium catalysts showed not only high activity but also remarkable selectivity to sugar alcohols reaching up to 81% yield of C4 to C6 sugar alcohols in aqueous phase with 7 h at 160 o C. 13 Although the HPAs are unique acid catalysts in the aqueous reaction, the high solubility in polar reaction media largely hinder their practical utilizations. So far, some efforts that impregnating HPAs onto or encapsulating it into porous carriers with high surface areas, such as silica, active carbon, zeolite, [14][15][16][17] and partially exchanging protons of the parent HPA with large inorganic cations like Cs + , K + , Rb + and NH 4 + , 18,19 have been made to separate the HAPs and reused them.…”

Transformation of Cellulose into Nonionic Surfactants Using a One‐Pot Catalytic Process

“…This is because of the hydrolysis of the robust crystalline structure of the cellulose still a challenge. [5] There are many examples reported in several reviews [1a,1b,6] on cellulose hydrolysis to obtain glucose with different acid catalysts such as mineral acids, [7] heteropolyacids, [8] ionic liquids, [9] supercritical water, [10] zeolites with metal particles, [11] metal oxides, [12] or sulfonated carbons, [13] as well as enzymes. [14] Nevertheless, product yields are often limited and there are several practical inconveniences.…”