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Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： Yi-Cong Wang Hui Zhat Pei-Yi Cheng Shu Zhang Xiang-Wei Liu Yi-Xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination method.This methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination method.The catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky effect.The vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ligand.Moreover,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Synergistic utilization of carbon sources for efficient biosynthesis of N-acetylglucosamine

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Green chemical engineering 2023年第2期4卷 233-238页

作者： Yanni Pei Yuhan Wang Xiaolin Shen Jia Wang Xinxiao Sun Qipeng Yuan State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

N-acetylglucosamine(GlcNAc)is an amino monosaccharide that has a variety of bioactivities and is widely used in pharmaceutical and food industries.Production of GlcNAc by chitin hydrolysis is limited by the supply of raw materials and encounters the risk of shellfish protein contamination.For efficient biosynthesis of GlcNAc,one challenge is to balance the carbon distribution between growth and production.Here,we applied the strategy of synergistic carbon utilization,in which glycerol supports cell growth and provides the acetyl group of GlcNAc while glucose serves as the precursor to glucosamine.The efficiency of GlcNAc production was stepwise improved by blocking the product re-uptake and degradation,strengthening the biosynthetic pathway and synergistically utilizing two carbon sources.With these efforts,the final strain produced 41.5 g/L GlcNAc with a yield of 0.49 g/g of total carbon sources.In addition,we also explored the feasibility of using acetate as a cheap carbon source to partly replace glycerol.This study provides a promising alternative strategy for sustainable and efficient pro-duction of GlcNAc.

关键词： N-Acetylglucosamine Synergistic carbon utilization Glucose facilitated diffusion system Acetate

Comprehensive treatment of latex wastewater and resource utilization of concentrated liquid

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Chinese Journal of chemical engineering 2023年第5期57卷 183-192页

作者： Shichao Tian Yuming Tu Rujie Li Yufan Du Zhiyong Zhou Fan Zhang Zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.

关键词： Latex wastewater resource utilization Forward osmosis Reverse osmosis Concentrated liquid

Efficient selective activation of sorbitol C–O bonds over C–C bonds on CoGa(221)generated by lattice-induction strategy

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Nano Research 2023年第5期16卷 6200-6211页

作者： Ying Kong Yanru Zhu Zhe An Jian Zhang Xin Shu Hongyan Song Qipeng Yuan Jing He State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Sorbitol is a primary platform compound in the conversion of cellulose.The conversion of sorbitol to C_(6) hydrocarbons requires a complete cleavage of C–O bonds and meanwhile the inhibition of C–C cleavage.Here,we demonstrated an efficient selective cleavage of C–O over C–C bond on the(221)facet of supported CoGa.A selectivity of 94%to C_(6) hydrocarbon with conversion of 97%has been achieved.The selective C–O cleavage was demonstrated by tuning the exposed facet as(221)or(110).The supported CoGa was prepared simply by reduction of Co and Ga-containing layered double hydroxides(CoZnGaAl-LDHs),the exposed facets of CoGa crystallites were controlled by tailoring the temperature-programmed rate in the reduction.By reducing CoZnGaAl-LDHs,CoGa(221)was exposed with a temperature-programmed rate of 5℃/min under the induction of ZnO lattice,while CoGa(110)was exposed with a rate of 10℃/min.

关键词： biomass supported CoGa facet exposure preferred C–O activation liquid hydrocarbons

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

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Frontiers of chemical Science and engineering 2023年第6期17卷 749-758页

作者： Ruiqi Li Kang Li Wei Wang Fan Zhang Shichao Tian Zhongqi Ren Zhiyong Zhou State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Since lithium iron phosphate cathode material does not contain high-value metals other than lithium,it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials.Here,we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield.Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions.Iron is retained in the leaching residue as iron phosphate,which is easy to recycle.The effects of factors such as acid concentration,acid dosage,amount of oxidant,and reaction temperature on the leaching of lithium and iron are comprehensively explored,and the mechanism of selective leaching is clarified.This process greatly reduces the cost of processing equipment and chemicals.This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.

关键词： lithium iron phosphate powder stoichiometric number selective leaching lithium recovery

Adsorption of rubidium ion from aqueous solution by surface ion imprinted materials

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Chinese Journal of chemical engineering 2023年第2期54卷 1-10页

作者： Zhongqi Ren Jie Wang Hewei Zhang Fan Zhang Shichao Tian Zhiyong Zhou State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

A new type of rubidium ion-imprinted polymer has been synthesized by the surface-imprinting technique using methacrylic acid as the functional monomer,the rubidium ion as the template,methanol as the solvent,and silica as a carrier.Ethylene glycol dimethacrylate and 2,2-azobisisobutyronitrile were used as acrosslinker and an initiator,respectively.In addition,based on the macrocyclic effect of crown ethers,the 18-crown-6 ligand was introduced as a ligand to fix the template ions better.Scanning electron microscopy,zeta-potential analysis,Fourier transform infrared spectroscopy,thermogravimetric analysis,and X-ray photoelectron spectroscopy were performed to characterize the ion-imprinted polymer.The effects of the preparation and adsorption conditions on the adsorption performance of the rubidium ion-imprinted polymer were investigated.The results indicated that the rubidium ion-imprinted polymer has high selectivity and faster kinetics than other adsorbents,with an equilibrium adsorption capacity of 200.19 mg·g^(-1)at 298 K within 25 min.The sorption isotherm was well described by the Freundlich isotherm model,while the adsorption kinetics fitted the pseudo-second-order kinetic model.Consecutive adsorption-desorption experiments showed that the ion-imprinted polymer had good chemical stability and reusability.

关键词： Surface-imprinted material Adsorption Aqueous solution Silica Selectivity

Co-thermal in-situ reduction of inorganic carbonates to reduce carbon-dioxide emission

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Science China Chemistry 2023年第4期66卷 1201-1210页

作者： Zhen Xue Jingyi Guo Shasha Wu Wenfu Xie Yujing Fu Xiaojie Zhao Kui Fan Ming Xu Hong Yan Mingfei Shao Xue Duan State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Thermal decomposition of inorganic metal carbonates is the main path to prepare metal oxides;nonetheless,it is always accompanied by the emission of large amounts of CO_(2) as one of the gas products.This study reports a concept of co-thermal insitu reduction of inorganic carbonates by using the energy released by carbonate decomposition under pure hydrogen atmosphere,which reduces the decarboxylation temperature and significantly inhibits the CO_(2) emissions.A combination of hydrogen–deuterium exchange,isotope experiment,and density functional theory calculations demonstrates that the CO results from the selective cleavage of Ca–O bonds at the surface of CaCO_(3) via the direct hydrogenation mechanism at relatively low temperature.However,it undergoes the reverse water–gas shift reaction path at high temperature,i.e.,CO being produced by the reduction of CO_(2) released by the decomposition of carbonates.This study sheds light on the potential of green hydrogen technology for inorganic carbonate valorization toward high value-added products,which can facilitate the large-scale industrial applications.

关键词： inorganic carbonate co-thermal in-situ reduction carbon dioxide emission reduction carbon monoxide

Low temperature one-pot synthesis of 1,1-diethoxyethane from ethanol on Bi/BiCeO_(x)with strong metal-support interactions

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Nano Research 2023年第3期16卷 3709-3718页

作者： Zhe An Jiayu Liu Meng Cao Jian Zhang Yanru Zhu Hongyan Song Xu Xiang Jing He State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenation of alcohol to acetaldehyde requires high temperature to activate oxygen to realize the C-H cleavage,while the acetalization of acetaldehyde with ethanol is exothermic reversible reaction favorable at low temperature.The mismatching of the reaction condition for the two consecutive steps makes it a great challenge to achieve both high ethanol conversion and high DEE selectivity.This work reports a highly efficient bi-functional catalysis by Bi/BiCeO_(x)for one-pot oxidative dehydrogenation-acetalization route from ethanol to DEE under 150℃and ambient pressure,affording a selectivity of 98.5%±0.5%to DEE at an ethanol conversion of 87.0%±1.0%.An efficient tandem catalysis has been achieved on the interfacial Bi^(δ)+-Ov-Ce^(III)sites in Bi/BiCeO_(x)established by strong metal-support interaction,in which Biδ+-Ov-sites contribute to the oxidative dehydrogenation of ethanol at mild temperature,and-Ov-CeIII sites to the subsequent acetalization between the generated acetaldehyde and ethanol.

关键词： ethanol conversion 1 1-diethoxyethane strong metal-support interaction Biδ+-Ov-CeIII sites

Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation,one-stage urea complexation and five-stage solvent crystallization

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中国化学工程学报:英文版 2023年第7期59卷 61-71页

作者： Yingxi Gao Jiayi Shi Jie Wang Fan Zhang Shichao Tian Zhiyong Zhou Zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult.A new combined process of molecular distillation,urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials.First,according to the difference in the mean free path of fatty acids,molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18-C20 fatty acids of stearic,oleic,linoleic,and linolenic acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes,in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of C22-C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification(SPOMFs)ratio as 0.6.In addition,all saturated fatty acids were basically separated.Finally,according to the difference in the solubility of fatty acids in solvents,the C18-C20 unsaturated fatty acids of oleic,linoleic,and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization.The content of C18-C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization innovatively adopted

关键词： Nervonic acid Acer truncatum Bunge Molecular distillation Urea complexation Solvent crystallization