Valorization of native birch wood lignin into monomeric phenols over nickel-based catalysts has been studied. High chemoselectivity to aromatic products was achieved by using Ni-based catalysts and common alcohols as solvents. The results show that lignin can be selectively cleaved into propylguaiacol and propylsyringol with total selectivity >90% at a lignin conversion of about 50%. Alcohols, such as methanol, ethanol and ethylene glycol, are suitable solvents for lignin conversion. Analyses with MALDI-TOF and NMR show that birch lignin is first fragmented into smaller lignin species consisting of several benzene rings with a molecular weight of m/z ca. 1100 to ca. 1600 via alcoholysis reaction. The second step involves the hydrogenolysis of the fragments into phenols. The presence of gaseous H 2 has no effect on lignin conversion, indicating that alcohols provide active hydrogen species, which is further confirmed by isotopic tracing experiments. Catalysts are recycled by magnetic separation and can be reused four times without losing activity. The mechanistic insights from this work could be helpful in understanding native lignin conversion and the formation of monomeric phenolics via reductive depolymerization. Broader contextNature efficiently synthesizes aromatic structures and deposits them as lignin in plants. Incorporation of catalytic technologies into lignin conversion is a possible option for valorizing the feedstock as a renewable raw material for aromatic chemical production. Use of heterogeneous catalysts facilitates separation and recycling, and has attracted great attention. However, the detailed chemistry between solid catalysts and solid feedstocks still remains unknown because of mass transfer limitations. Herein we report the valorization of native birch wood lignin into monomeric phenols over nickel-based catalysts. High chemoselectivity to aromatic products was achieved by using Ni-based catalysts and common alcohols as solvents. The results show that lignin can be selectively cleaved into propylguaiacol and propylsyringol with total selectivity >90% at a lignin conversion of about 50%. Analysis results show that birch lignin is rst fragmented into smaller lignin species consisting of several benzene rings with a molecular weight of m/z ca. 1100 to ca. 1600 via alcoholysis reaction. The second step involves the hydrogenolysis of the fragments into phenols. This study will greatly contribute to the understanding of the lignin depolymerization reaction and will be interesting for other biomass conversion.

An acid-assisted ultrarapid thermal strategy is developed for constructing specifically functionalized graphene. The electrochemical performance of functionalized graphene can be boosted via elaborate coupling between the pseudocapacitance and the electronic double layer capacitance through rationally tailoring the structure of graphene sheets. This presents an opportunity for developing further high-performance graphene-based electrodes to bridge the performance gap between traditional capacitors and batteries.

The use of a heterogeneous Lewis acid catalyst, which is insoluble and easily separable during the reaction, is a promising option for hydrolysis reactions from both environmental and practical viewpoints. In this study, ceria showed excellent catalytic activity in the hydrolysis of 4-methyl-1,3-dioxane to 1,3-butanediol in 95% yield and in the one-pot synthesis of 1,3-butanediol from propylene and formaldehyde via Prins condensation and hydrolysis reactions in an overall yield of 60%. In-depth investigations revealed that ceria is a water-tolerant Lewis acid catalyst, which has seldom been reported previously. The ceria catalysts showed rather unusual high activity in hydrolysis, with a turnover number (TON) of 260, which is rather high for bulk oxide catalysts, whose TONs are usually less than 100. Our conclusion that ceria functions as a Lewis acid catalyst in hydrolysis reactions is firmly supported by thorough characterizations with IR and Raman spectroscopy, acidity measurements with IR and (31)P magic-angle-spinning NMR spectroscopy, Na(+)/H(+) exchange tests, analyses using the in situ active-site capping method, and isotope-labeling studies. A relationship between surface vacancy sites and catalytic activity has been established. CeO(2)(111) has been confirmed to be the catalytically active crystalline facet for hydrolysis. Water has been found to be associatively adsorbed on oxygen vacancy sites with medium strength, which does not lead to water dissociation to form stable hydroxides. This explains why the ceria catalyst is water-tolerant.

A unique MoS2@graphene nanocable with a novel contact model between MoS2 nanosheets and graphene has been developed for high-performance lithium storage.

We report a strategy for the catalytic conversion of lignosulfonate into phenols over heterogeneous nickel catalysts. Aryl-alkyl bonds (C-O-C) and hydroxyl groups (-OH) are hydrogenated to phenols and alkanes, respectively, without disturbing the arenes. The catalyst is based on a naturally abundant element, and is recyclable and reusable.

Over many years chemists have established the general principle that two-dimensional chemical structures constructed with pure sp 2 carbon atoms will definitely form an aromatic system with delocalized electron density. However, based on a recently proposed chemical structure, graphenylene, this rule may finally be broken. Herein, we predict the properties of a new two-dimensional sp 2-carbon network known as graphenylene, which is the first example of non-delocalized sp 2-carbon structure composed of cyclohexatriene units with three quite distinct CC bonds within a C6 ring. In addition, theoretical calculations demonstrate that graphenylene has periodic pores of 3.2 Å in diameter and is a semiconductor with a narrow direct band gap, making it promising for various applications, such as electronic devices and efficient hydrogen separation. This study provides a new perspective on carbon allotropes, leading to a better understanding of [N]phenylene based organic frameworks, as well as clarifying the relationship between benzene and cyclohexatriene. Besides graphite and diamond, which have already been known for thousands years, the family of carbon allotropes has suddenly under gone a rapid expansion in recent decades, particularly with the addition of forms such as fullerenes 1 , carbon nanotubes 2 and graphene 3. With its unique chemical character, carbon can bind with itself or other elements to generate not only countless organic compounds, but also new carbon allotropes. The combination of sp-, sp 2-and sp 3hybridized carbon atoms leads to many possible carbon allotropes 4-6 with different dimensionalities 7-13. Of all of these experimentally obtained or theoretically predicted materials, the family of sp 2-carbon allotropes, which include fullerenes, nanotubes and graphene, is the most fascinating and has recently attracted considerable attention owing to their remarkable properties and potential applications in many emerging technologies. However, it is worth noting that fullerene, nanotubes and graphene all possess delocalized π-conjugated bonding such that they have relatively uniform bond lengths and electron distributions. Graphene can be considered as a building unit that can be wrapped up into fullerenes, rolled into carbon nanotubes or stacked into graphite 14. From a theoretical point of view, all of them are similar carbon networks with the same structural unit. One interesting and scientifically important question is whether sp 2-carbon can form alternative net

A scalable, low-cost and environmentally benign strategy is developed for the facile construction of a unique kind of three-dimensional porous electrode architecture for high-performance lithium ion batteries. The methodology is based on the employment of pyrolyzed bacterial cellulose as a new three-dimensional porous scaffold to support various nanostructured active electrode materials, such as SnO2 and Ge.

Au nanoclusters with an average size of approximately 1 nm size supported on HY zeolite exhibit a superior catalytic performance for the selective oxidation of 5‐hydroxymethyl‐2‐furfural (HMF) into 2,5‐furandicarboxylic acid (FDCA). It achieved >99 % yield of 2,5‐furandicarboxylic acid in water under mild conditions (60 °C, 0.3 MPa oxygen), which is much higher than that of Au supported on metal oxides/hydroxide (TiO2, CeO2, and Mg(OH)2) and channel‐type zeolites (ZSM‐5 and H‐MOR). Detailed characterizations, such as X‐ray diffraction, transmission electron microscopy, N2‐physisorption, and H2‐temperature‐programmed reduction (TPR), revealed that the Au nanoclusters are well encapsulated in the HY zeolite supercage, which is considered to restrict and avoid further growing of the Au nanoclusters into large particles. The acidic hydroxyl groups of the supercage were proven to be responsible for the formation and stabilization of the gold nanoclusters. Moreover, the interaction between the hydroxyl groups in the supercage and the Au nanoclusters leads to electronic modification of the Au nanoparticles, which is supposed to contribute to the high efficiency in the catalytic oxidation of HMF to FDCA.