Zhen Wu

Bio: Zhen Wu is an academic researcher from Hohai University. The author has contributed to research in topics: Medicine & Hydrolysis. The author has an hindex of 13, co-authored 34 publications receiving 1142 citations. Previous affiliations of Zhen Wu include South China University of Technology.

Recent advances in catalytic transformation of biomass-derived 5-hydroxymethylfurfural into the innovative fuels and chemicals

Abstract: In contrast to the nonrenewable fossil resources, biomass, the only renewable resource of organic carbon in the nature, is considered as a special kind of inexhaustible feedstocks, which can be used for the synthesis of numerous valuable products in a sustainable manner. Among many biomass-derived products, 5-hydroxymethylfurfural (HMF) is identified to be a crucially important versatile compound due to its marvelous structure that is composed of an aldehyde group, a hydroxyl group and a furan ring. Hence, HMF possesses a very strong chemical reactivity, and it can be further transformed into a wide variety of value-added derivatives. In recent years, the synthetic methods, physicochemical properties and commercial prospects of HMF-based conventional derivatives such as 2,5-dimethylfuran (DMF), 5-ethoxymethylfurfural (EMF), ethyl levulinate (EL), long chain alkane (LLA), levulinic acid (LA), 2,5-diformylfuran (DFF) and 2,5-furandicarboxylic acid (FDCA) have been intensively reviewed by many researchers. However, up to now, the preparation of HMF-based innovative derivatives such as 2,5-dihydroxymethylfuran (DHMF), 2,5-dihydroxymethyltetrahydrofuran (DHMTHF), 1,2,6-hexanetriol (HTO), 1,6-hexanediol (HDO), 1-hydroxyhexane-2,5-dione (HHD), 3-hydroxymethylcyclopetanone (HMCPN), furan-2,5-dimethylcarboxylate (FDMC), maleic anhydride (MA), 5-hydroxy-5-(hydroxymethyl)furan-2(5H)-one (HHMFO), 5-alkoxymethylfurfural (AMF), 5,5-oxy-(bismethylene)-2-furaldehyde (OBMF), 5-arylaminomethyl-2-furanmethanol (AAMFM), 2,5-furandiamidine dihydrochloride (FDADHC), 1-alkyl-5-hydroxy-2-(hydroxymethyl)pyridinium (AHHMP), 5,5-bis(hydroxymethyl)furoin (BHMF), 5-(dialkyloxymethyl)-2-furanmethanol (DAMFM), 5-chloromethylfurfural (CMF), 5-alkanoyloxymethylfurfural (AOOMF) and furfuryl alcohol (FFA) has not yet been comprehensively summarized. In order to fill this gap, the latest studies and advancements on the preparation of HMF-based innovative derivatives via various catalytic approaches such as hydrogenation, oxidation, etherification, amination, condensation, halogenation, esterification and decarbonylation are systematically outlined and discussed in this review. Furthermore, a few potential research trends in the future studies are also proposed to provide some useful ideas for the further preparation of HMF-based innovative derivatives in a much more green, simple, efficient and economical way.

Chemocatalytic hydrolysis of cellulose into glucose over solid acid catalysts

Abstract: With the progressive increase in global energy demands and the continuous depletion of worldwide fossil resources, renewable lignocellulosic biomass has attracted more and more attention. As the most abundant component of lignocellulosic biomass, cellulose, which is a linear polymer formed by the repeating connection of glucose units through β-1,4-glycosidic linkages, is considered to be an inexhaustible raw material for the sustainable production of chemicals and fuels. For the effective utilization of cellulose, the primary and essential step is the hydrolysis of cellulose into glucose. Although homogeneous acids and cellulases are the most common catalysts for the hydrolysis of cellulose into glucose, they possess a series of problems such as reactor corrosion, waste treatment and poor recyclability and high cost, low efficiency and long reaction time, respectively. In order to overcome the above-mentioned drawbacks, solid acid catalysts have been increasingly employed for the hydrolysis of cellulose into glucose in recent years. In this review, the state-of-the-art studies on the hydrolysis of cellulose into glucose over various types of solid acid catalysts such as acid resins, metal oxides, H-form zeolites, heteropoly acids, functionalized silicas, supported metals, immobilized ionic liquids, carbonaceous acids and magnetic acids are systematically summarized. Meanwhile, reaction medias, auxiliary methods and neoteric strategies for the hydrolysis of cellulose into glucose are intensively discussed. Furthermore, some potential research trends in the future are also prospected to provide some valuable ideas for the hydrolysis of cellulose into glucose in a more green, simple, efficient and inexpensive way.

Selective Transformation of 5-Hydroxymethylfurfural into the Liquid Fuel 2,5-Dimethylfuran over Carbon-Supported Ruthenium

Abstract: A simple and efficient process was presented for the selective hydrogenation of 5-hydroxymethylfurfural (HMF) into the high-quality liquid fuel 2,5-dimethylfuran (DMF) in the presence of tetrahydrofuran (THF). Among the employed metal catalysts, the relatively inexpensive carbon-supported ruthenium (Ru/C) displayed the highest catalytic performance, which led to 94.7% DMF yield with 100% HMF conversion at a relatively mild reaction temperature of 200 °C for only 2 h. Although Ru/C had a little loss in the catalytic activity when it was used for five successive reaction runs, the partially deactivated Ru/C could be easily regenerated by heating at a mixed flow of H2 and N2. Moreover, the plausible mechanism involving an aldehyde group, a hydroxyl group, and a furan ring for the selective hydrogenation of HMF into DMF was also proposed. Subsequently, DMF was separated from the crude hydrogenation mixture according to their various boiling points by the combination of atmospheric distillation and vacuum dist...

Catalytic Conversion of Carbohydrates to Initial Platform Chemicals: Chemistry and Sustainability

Abstract: The replacement of fossil resources that currently provide more than 90% of our energy needs and feedstocks of the chemical industry in combination with reduced emission of carbon dioxide is one of the most pressing challenges of mankind. Biomass as a globally available resource has been proposed as an alternative feedstock for production of basic building blocks, which could partially or even fully replace the currently utilized fossil-based ones in well-established chemical processes. The destruction of lignocellulosic feed followed by oxygen removal from its cellulose and hemicellulose content by catalytic processes results in the formation of initial platform chemicals (IPCs). However, their sustainable production strongly depends on the availability of resources, their efficient or even industrially viable conversion processes, and replenishment time of feedstocks. Herein, we overview recent advances and developments in catalytic transformations of the carbohydrate content of lignocellulosic biomass ...

Catalytic Transformation of Lignocellulose into Chemicals and Fuel Products in Ionic Liquids

Abstract: Innovative valorization of naturally abundant and renewable lignocellulosic biomass is of great importance in the pursuit of a sustainable future and biobased economy. Ionic liquids (ILs) as an important kind of green solvents and functional fluids have attracted significant attention for the catalytic transformation of lignocellulosic feedstocks into a diverse range of products. Taking advantage of some unique properties of ILs with different functions, the catalytic transformation processes can be carried out more efficiently and potentially with lower environmental impacts. Also, a new product portfolio may be derived from catalytic systems with ILs as media. This review focuses on the catalytic chemical conversion of lignocellulose and its primary ingredients (i.e., cellulose, hemicellulose, and lignin) into value-added chemicals and fuel products using ILs as the reaction media. An outlook is provided at the end of this review to highlight the challenges and opportunities associated with this interes...

How Catalysts and Experimental Conditions Determine the Selective Hydroconversion of Furfural and 5-Hydroxymethylfurfural.

Abstract: Furfural and 5-hydroxymethylfurfural stand out as bridges connecting biomass raw materials to the biorefinery industry. Their reductive transformations by hydroconversion are key routes toward a wide variety of chemicals and biofuels, and heterogeneous catalysis plays a central role in these reactions. The catalyst efficiency highly depends on the nature of metals, supports, and additives, on the catalyst preparation procedure, and obviously on reaction conditions to which catalyst and reactants are exposed: solvent, pressure, and temperature. The present review focuses on the roles played by the catalyst at the molecular level in the hydroconversion of furfural and 5-hydroxymethylfurfural in the gas or liquid phases, including catalytic hydrogen transfer routes and electro/photoreduction, into oxygenates or hydrocarbons (e.g., furfuryl alcohol, 2,5-bis(hydroxymethyl)furan, cyclopentanone, 1,5-pentanediol, 2-methylfuran, 2,5-dimethylfuran, furan, furfuryl ethers, etc.). The mechanism of adsorption of the ...

Recent catalytic routes for the preparation and the upgrading of biomass derived furfural and 5-hydroxymethylfurfural

Abstract: Furans represent one of the most important classes of intermediates in the conversion of non-edible lignocellulosic biomass into bio-based chemicals and fuels. At present, bio-furan derivatives are generally obtained from cellulose and hemicellulose fractions of biomass via the acid-catalyzed dehydration of their relative C6-C5 sugars and then converted into a wide range of products. Furfural (FUR) and 5-hydroxymethylfurfural (HMF) are surely the most used furan-based feedstocks since their chemical structure allows the preparation of various high-value-added chemicals. Among several well-established catalytic approaches, hydrogenation and oxygenation processes have been efficiently adopted for upgrading furans; however, harsh reaction conditions are generally required. In this review, we aim to discuss the conversion of biomass derived FUR and HMF through unconventional (transfer hydrogenation, photocatalytic and electrocatalytic) catalytic processes promoted by heterogeneous catalytic systems. The reaction conditions adopted, the chemical nature and the physico-chemical properties of the most employed heterogeneous systems in enhancing the catalytic activity and in driving the selectivity to desired products are presented and compared. At the same time, the latest results in the production of FUR and HMF through novel environmental friendly processes starting from lignocellulose as well as from wastes and by-products obtained in the processing of biomass are also overviewed.

Review: Sustainable production of hydroxymethylfurfural and levulinic acid: Challenges and opportunities

Abstract: Hydroxymethylfurfural (HMF) and levulinic acid (LA) are two of the most promising chemicals derived from biomass owing to their convertibility into a large number of chemicals having applications in diverse industries. Their transition from niche products to mass-produced chemicals, however, requires their production from sustainable biomass feedstocks at low costs using environment-friendly techniques. In this review, the numerous reaction systems that have been developed to produce HMF and LA from various substrates have been looked at and their merits, demerits and requirements for commercialisation outlined. Special attention has been paid to microwave irradiation-heated systems due to their dual advantages of high product yields and low environmental footprint.