Zeolites are important in many chemical synthesis and petrochemical processes. The economic and environmental requirements motivate the persisting exploration of the zeolite structure-performance relationship and the rational design of catalysts.
　　Recently, a research team led by Profs. LIU Zhongmin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) revealed the dynamic evolution of aluminum coordination environments in mordenite (MOR) zeolite.
　　This study was published in Angewandte Chemie International Edition on August 1.
　　The researchers found that a facile treatment with pyridine could force the octahedral coordination Al back into a tetrahedral environment, which could increase the number of available active sites and enhance the diffusion of dimethyl ether, thus improving (by four times) the reactivity of the dimethyl ether carbonylation reaction and prolonging the lifetime of catalysts.
　　Then, they investigated the dynamic evolution of aluminum coordination environments in mordenite zeolite along with treatment conditions.
　　They found that all Al species adopted tetrahedral framework coordination in the NH4-MOR sample. NH4-MOR transformed into proton form after calcination, leading to the formation of Brønsted acid sites (BASs). Meanwhile, part of the framework tetrahedral Al was changed geometry into the octahedral coordination, which was demonstrated as framework-associated Al, yielding Lewis acid sites (LASs).
　　Upon pyridine adsorption, different Al species in distinct 8-membered ring (MR) and 12-MR topological spaces occurred complex interactions with pyridine. In the 12-MR channel, the pyridine molecule bonded with BASs, thereby poisoning the acid sites. Moreover, pyridine acted on the octahedral coordination Al species, causing the LASs-pyridine species, which converted the nonframework Al species into tetracoordination.
　　They observed the adsorption and desorption behaviors of pyridine on the BASs within the 8-MR channel, and found that there was no effect on the BASs within 8-MR channels by pyridine in this pyridine adsorption condition. In contrast, adsorbed pyridine forced the octahedral coordination Al species in the 8-MR back into the zeolite framework, thus yielding more BASs in the 8-MR channel.
　　Therefore, the pyridine adsorption was helpful in obtaining a MOR catalyst with more framework Al atoms in the 8MR channel, and the acid sites in the 12-MR channel were deactivated, thereby enhancing the dimethyl ether conversion and prolonging the lifetime of protonic MOR zeolite.
　　The above work was supported by the National Natural Science Foundation of China. (Text by LIU Rongsheng and YU Zhengxi)

Methane, mainly from natural gas, shale gas and methane hydrate, is one of the most economic fossil fuels. However, it remains a great challenge to realize the selective valorization of methane under mild conditions due to the inherently small polarizability and high dissociation energy of C-H bond in CH4 as well as the higher reactivity of target oxygenates. Recently, a research group led by Prof. WANG Xiaodong and Prof. LIN Jian from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. ZHU Chun from Guizhou University, has developed UiO-66 metal-organic frameworks (MOFs) catalysts with tunable electronic property, which could enhance the selective oxidation of methane. This study was published in Angewandte Chemie International Edition on June 29. 
　　The UiO-66-X catalyst directly convert CH4 to oxygenates with 100% selectivity by using H2O2 as an oxidant (Image by FANG Geqian) The over-oxidation of target products and the metal sites leaching are usually unavoidable on the supported metal species. Meanwhile, the structured metal-oxo species on bulk metal oxides or frameworks are inferior reactivity, and they just play as a support or co-catalyst to enhance the CH4 conversion. To solve the above challenges, the researchers developed the sole UiO-66 MOFs catalysts modified by various ligands (NH2-BDC, H2BDC, and NO2-BDC) to directly convert CH4 to oxygenates with 100% selectivity by using H2O2 as an oxidant under mild conditions. The Zr-oxo nodes with these modifiers exhibited different electronic properties that affected the anchoring of ·OH species to form effective Zroxo-·OH sites, which can promote the activation of the C-H bond of CH4 with the lowest energy barrier over UiO-66-H. The above work was supported by the National Natural Science Foundation of China, Youth Innovation Promotion Association of CAS, and Dalian Science Foundation for Distinguished Young Scholars. (Text by FANG Geqian) 

　　A research team led by Prof. WU Xiaofeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has realized the palladium-catalyzed difluoroalkylative carbonylation of styrenes toward difluoropentanedioates.
　　This study was published in Chemical Science on August 3.
　　Organic fluorides play an important role in organic synthesis, especially in medicinal chemistry and materials science. Among them, difluoromethylene has good metabolic stability, and its electron-absorbing property can affect the electronic and chemical properties of adjacent functional groups, thus it is present in a variety of drug molecules and bioactive molecules.
　　However, the fluoroalkylation carbonylation of aryl olefins remains a challenge due to their strong tendency to oligometrize and polymerize.
　　In this study, the researchers developed a new method for carbonylation of aryl olefins by palladium-catalyzed difluoroalkylation.
　　They used inexpensive industrial reagent ethyl bromodifluoroacetate both as a difluorinated precursor and as a nucleophilic reagent, and converted a variety of aryl olefins to the corresponding difluoroglutaryl compounds in good yields, with broad functional group tolerance and excellent selectivity.
　　The reaction could be scaled up to 3 mmol, and the product difluoroglutarate compounds could be efficiently converted to the corresponding diacids and diols. (Text by BAO Zhipeng)

Ferroelectrics are photocatalytic candidates for solar fuel production. However, the performance of ferroelectric photocatalysts is often moderate, which could not achieve overall water splitting.Recently, a research team led by Prof. LI Can and Prof. FAN Fengtao from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) proposed a new charge separation strategy to fabricate interfacial charge-collecting nanostructures on positive and negative domains of ferroelectric, which enables water splitting in ferroelectric photocatalysts.This study was published in Nature Communications on July 22.Bipolar charge collecting structure enables overall water splitting on ferroelectric photocatalysts (Image by LIU Yong)The researchers chose the ferroelectric BaTiO3 single domain crystal and Au nanoparticle as a model system to highlight the charge separation mechanism at Au/BaTiO3 interface. They observed that photogenerated electrons and holes accumulated efficiently within their thermalization length (around 50 nm) around Au nanoparticles located in the positive and negative domains of a BaTiO3 single crystal, respectively.They found that the measured thermalization length was an essential experimental prescription for fabricating high-efficiency photocatalytic and photovoltaic devices on the nanoscale. With this structure design, constructed ferroelectric photocatalysts could perform photocatalytic overall water splitting."The fabrication of bipolar charge-collecting structures on ferroelectrics to achieve overall water splitting may set a paradigm for utilizing the energetic photogenerated charges in solar energy conversion," said Prof. FAN.The above work was supported by the Fundamental Research Center of Artificial Photosynthesis (FReCAP), the National Natural Science Foundation of China, CAS Projects for Young Scientists in Basic Research, the National Key R&D Program of China, DICP Innovation Foundation and Fellowship of China Postdoctoral Science Foundation. (Text by LIU Yong)

Enantiopure-fused azetidines, the privileged structural motifs, are widespread in natural products and medically relevant molecules. It's important to develop efficient catalytic systems for the rapid assembly of such important frameworks.Recently, a research team led by Prof. CHEN Qing'an from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a chiral phosphoric acid (CPA) catalyzed multicomponent reaction of anilines, aldehydes, and azetidinones to access tetrahydroquinoline-fused azetidines with three contiguous stereocenters.Their findings were published in Chem Catalysis on June 20.In this work, the researchers developed the chiral phosphoric acid (CPA) catalysis using commercially available anilines, benzaldehydes, and azetidinones as starting materials. This protocol enabled the one-step construction of three contiguous stereocenters with high diastereo- and enantioselectivities.DFT calculations implied that a stepwise mechanism consisting of enamine-imine addition and Friedel-Crafts attack is likely involved."This work not only provides an efficient alternative to access chiral fused azetidines, but also opens up an avenue to design other asymmetric multicomponent reaction," said Prof. CHEN.The research was supported by Dalian Outstanding Young Scientific Talent, and the National Natural Science Foundation of China. (Text by HU Yancheng)

Fatty acids and their derivatives are promising raw materials for manufacturing advanced biofuels, detergents, lubricants, surfactants and so on. Current supply of fatty acids is mainly through extraction from plants, which requires large amounts of arable land.Methanol is an ideal and renewable feedstock for bio-manufacturing. Methanol biotransformation might provide a sustainable route for fatty acid production with independence of arable land and fresh water.Recently, a research group led by Prof. ZHOU Yongjin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has engineered yeast Ogataea polymorpha for efficient productions of free fatty acids (FFA) from sole methanol by rewiring cellular metabolism and relieving the methanol toxicity.This study was published in Nature Metabolism on July 11.Yeast is widely used for baking and brewing, which is an ideal host for methanol-based bio-manufacturing. However, cellular methanol metabolism is highly regulated and methanol toxicity might limit the biosynthetic efficiency. In particular, there is limited information connecting methanol toxicity, methanol metabolism and product biosynthesis.The researchers observed growth deficiency of engineered FFA producing Ogataea polymorpha in methanol, and this deficiency was restored by adaptive laboratory evolution. Multi-omics analysis (genomics, transcriptomics and lipidomics) showed that FFA overproduction perturbed phospholipid hemostasis.A metabolic rewiring in this superior host achieved a high level of FFA accumulation (up to 15.9 g/L)."This work reveals the mechanisms of methanol toxicity during bio-productions, and achieves efficient methanol biotransformation to value-added products for industrial applications," Prof. ZHOU said. (Text by GAO Jiaoqi)