Lignin is the only large-volume renewable source of aromatic chemicals. Efficient depolymerization and deoxygenation of lignin while retaining the aromatic functionality are attractive but extremely challenging. Here we report the selective production of arenes via direct hydrodeoxygenation of organosolv lignin over a porous Ru/Nb2O5 catalyst that enabled the complete removal of the oxygen content from lignin. The conversion of birch lignin to monomer C7–C9 hydrocarbons is nearly quantitative based on its monomer content, with a total mass yield of 35.5 wt% and an exceptional arene selectivity of 71 wt%. Inelastic neutron scattering and DFT calculations confirm that the Nb2O5 support is catalytically unique compared with other traditional oxide supports, and the disassociation energy of Caromatic–OH bonds in phenolics is significantly reduced upon adsorption on Nb2O5, resulting in its distinct selectivity to arenes. This one-pot process provides a promising approach for improved lignin valorization with general applicability.

NiO with novel flower-like morphology was prepared by using a two-step, template-and surfactant-free, environmentally friendly method. Flower-like NiO was composed of many irregular nanosheets that were assembled together by weak interactions. The as-prepared materials were characterized by X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy with selected area electron diffraction patterns, N 2 sorption, temperature-programmed reduction with CO, X-ray photoelectron spectroscopy (XPS), and in situ Fourier transform infrared (FT-IR) for CO adsorption. The catalytic behaviors for CO oxidation were studied by using a fixed bed microreactor. Compared to NiO nanoparticles, we found the flower-like NiO possessed a larger surface area, bimodal pore size distribution, higher reducibility, and superior catalytic activity for CO oxidation. The XPS and CO in situ FT-IR results showed that its catalytic property was morphology dependent. The flower-like morphology provided more coordinate unsaturated Ni atoms, more oxygen vacancies, and more defect sites, which made the flower-like NiO have a strong interaction with CO and more active sites for catalytic reactions. Further studies showed that a mild condition for thermodecomposition of the precursor was necessary to preserve the flower-like morphology because of the large discrepancy of the crystalline cell structures between the β-Ni(OH) 2 precursor and product of NiO.

Low-temperature NH3-SCR has attracted considerable attention owing to the vast demand in industrial furnaces and its energy-conserving feature. This review summarizes the recent advances in the application of ceria-based catalysts for low-temperature NH3-SCR.

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Conversion of lignin into monocyclic hydrocarbons as commodity chemicals and drop-in fuels is a highly desirable target for biorefineries. However, this is severely hindered by the presence of stable interunit carbon-carbon linkages in native lignin and those formed during lignin extraction. Herein, we report a new multifunctional catalyst Ru/NbOPO4 that achieves the first example of catalytic cleavage of both interunit C-C and C-O bonds in one-pot lignin conversions, yielding 124-153% of monocyclic hydrocarbons; that is 1.2-1.5 times those yields obtained from the established nitrobenzene oxidation method. This catalyst also exhibits high stability and selectivity (up to 68%) to monocyclic arenes over repeated cycles. The mechanism of the activation and cleavage of 5-5 C-C bonds in biphenyl, as a lignin model adopting the most robust C-C linkages, has been revealed via in situ inelastic neutron scattering, coupled with modelling. This study breaks the conventional theoretical limit on lignin monomer production.

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Purpose In multiple cell metazoans, the ability of polarized epithelial cells to convert to motile mesenchymal cells in order to relocate to another location is governed by a unique process termed epithelial-mesenchymal transition (EMT). While being an essential process of cellular plasticity for normal tissue and organ developments, EMT is found to be involved in an array of malignant phenotypes of tumor cells including proliferation and invasion, angiogenesis, stemness of cancer cells and resistance to chemo-radiotherapy. Although EMT is being extensively studied and demonstrated to play a key role in tumor metastasis and in sustaining tumor hallmarks, there is a lack of clear picture of the overall EMT signaling network, wavering the potential clinical trials targeting EMT. Methods In this review, we highlight the potential key therapeutic targets of EMT linked with tumor aggressiveness, hypoxia, angiogenesis and cancer stem cells, emphasizing on an emerging EMT-associated NF-κB/HER2/STAT3 pathway in radioresistance of breast cancer stem cells. Results Further definition of cancer stem cell repopulation due to EMT-controlled tumor microenvironment will help to understand how tumors exploit the EMT mechanisms for their survival and expansion advantages. Conclusions The knowledge of EMT will offer more effective targets in clinical trials to treat therapy-resistant metastatic lesions.

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