Molecular Catalysis
·
2024
·
IF 3.9
Guili Luan,Guihua Yang,Hongyu Wang,Jiaxuan Li,Haojie Sun,Mengyao Sun,Changfei Shi,Shitao Yu,Ji-Jun Zou,Genkuo Nie
(Alkyl-)cyclohexane diols are of high value as industrial reagents and resources, but current producing methods are still unsustainable. Herein, a new method of producing (alkyl-)cyclohexane diols using lignin derived phenols with yield as high as 91.2 % by selective hydrogenolysis is firstly achieved over Nb 2 O 5 and Ni/MCM-41. The hydrogenolysis is completed by designing two-step reactions compositing of selective crack of C(sp 3 )-O bond and selective hydrogenation of benzene ring of lignin derived phenols to achieve a high selectivity. Nb 2 O 5 demonstrates superior activity and long-life time in C(sp 3 )-O bond cleavage compared to commercial solid acids. The robust catalytic performance was thoroughly analyzed through detailed characterization and attributed to the abundant oxygen vacancies produced, which lead more strong L acids and adsorb the methoxy group in lignin derived phenols and at the same time interact with the acid sites to facilitate the cleavage of the C(sp 3 )-O bond. The consequent selective hydrogenation of benzene ring is completed by Ni/MCM-41 easily. More lignin derived phenols are explored in this reaction with (alkyl-)cyclohexane diols universally synthesized. This work provides a new application of lignin derived phenols to synthesize value-added chemicals and makes contribution to sustainable development by biorefineries.
研究领域:
化学工程
·
催化
·
可持续化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2024
·
IF 2.5
Bo Zhang,Chengyang Niu,Wenlong Chu,Xuehao Guo,Xilong Zhou,Cheng Li,Xiulian Fan,Luwei Zou,Zhaofeng Wu,Yunzhang Lu,Fangping OuYang,Yu Zhou,Hongyan Zhang
Niobium-based oxides with wide bandgap and high dielectric constant show great potential in the applications of electronic and optoelectronic devices. Herein, the quasi-van der Waals epitaxial growth of 2D α-Nb 2 O 5 nanosheets is reported, in which the growth promoter of sulfur and alkali halides has been utilized to catalyze the ultrathin 2D growth. The relatively low Gibbs free energy of α-Nb 2 O 5 nanosheets can drive the ultrathin growth down to 30 nm on the c-Al 2 O 3 substrate by the transformation of T-Nb 2 O 5 powder sources without any doping effects, demonstrating the diverse α-Nb 2 O 5 nanostructure morphologies. The as-grown α-Nb 2 O 5 nanosheets are characterized with high crystalline quality and specific dominated growth plane, indicating the uniform dielectric properties. The metal–insulator–metal capacitor has confirmed the α-Nb 2 O 5 nanosheet with a high dielectric constant over 40. The dual promoters’ growth design strategy provides a universal synthesis method for the 2D nonlayered dielectric materials.
研究领域:
材料科学
·
纳米技术
·
电子与光电子
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·
IF 4.914
Yaxuan Jing,Yu Xin,Yong Guo,Xiaohui Liu,Yanqin Wang
Aldol condensation is of significant importance for the production of fuel precursors from biomass-derived chemicals and has received increasing attention. Here we report a Nb 2 O 5 catalyst with excellent activity and stability in the aldol condensation of biomass-derived carbonyl molecules. It is found that in the aldol condensation of furfural with 4-heptanone, Nb 2 O 5 has obviously superior activity, which is not only better than that of other common solid acid catalysts (ZrO 2 and Al 2 O 3 ), more importantly, but also better than that of solid base catalysts (MgO, CaO, and magnesium-aluminum hydrotalcite). The detailed characterizations by N 2 sorption/desorption, NH 3 -TPD, Py-FTIR and DRIFTS study of acetone adsorption reveal that Nb 2 O 5 has a strong ability to activate the C=O bond in carbonyl molecules, which helps to generate a metal enolate intermediate and undergo the nucleophilic addition to form a new C–C bond. Furthermore, the applicability of Nb 2 O 5 to aldol condensation is extended to other biomass-derived carbonyl molecules and high yields of target fuel precursors are obtained. Finally, a multifunctional Pd/Nb 2 O 5 catalyst is prepared and successfully used in the one-pot synthesis of liquid alkanes from biomass-derived carbonyl molecules by combining the aldol condensation with the sequential hydrodeoxygenation .
研究领域:
催化
·
化学工程
·
可再生能源
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Fang Xu,Yan Yang,Xiaolei Shi,Yulong Liao,Yonggang Liu,Xueying Wang,Fei Xie,Jianbo Hu
Interest in improving the magnetic properties by co-doping has thrived since it is demonstrated that such co-doping can be used to control the microstructure of ferrites at a low sintering temperature . Usually this process involves grain growth and densification by liquid phase sintering or, in some cases, abnormal growth of grain. Here, we study the growth mechanism of the low-sintered LiZnTi ferrites doped with additions of Nb 2 O 5 and Li 2 CO 3 -MgO-ZnO-B 2 O 3 -SiO 2 (LMZBS) glass through characterization of microstructure and magnetic properties. SEM results show that along with the increase of LMZBS glass contents, the change of ferrite grain presents three different stages. At the initial stage, densification of grain is dominant and grain growth is unconspicuous. Due to the increase of LMZBS glass content, the main process at the second stage is grain growth. At the last stage, however, grain growth starts to be suppressed and pores appear again because of competition between the two additives. Corresponding to each stage, the magnetic parameters of the LiZnTi ferrites, including 4π M s , H ci , B s , B r / B s and Δ H , have different trends. Moreover, XRD patterns show that all samples have a pure spinel phase, which means influence of the two additives on crystal structure is negligible. All in all, we obtain a LiZnTi ferrite with uniform and compact microstructure, high saturation flux density ( B s = 294.2 mT), remanence ratio ( B r / B s = 0.87), saturation magnetization (4π M s = 3700.1 G) and low ferromagnetic resonance linewidth (Δ H = 253) at 900 °C.
研究领域:
材料科学
·
磁学
·
陶瓷
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Congyue Zhao,Chunling Li,Minghui Chen,Tianqi Niu,Qian Zhao,Tianjun Ni,Dong Yan,Weidong Wu,Dong Liu
The exploitation of an efficient way to treat antineoplastic doxorubicin hydrochloride (DOX) is critical due to its harmful effects on the ecological system and human health. Recently, photocatalysis has emerged as one of the most feasible strategies to resolve this crisis. However, the development of novel catalysts with highly efficient photocatalytic activity still remains a great challenge. Herein, a novel 0D/3D Nb 2 O 5 QDs/C-doped g-C 3 N 4 type-II heterojunction with outstanding adsorption and photocatalytic degradation capacities for DOX was developed based on combining elemental doping, morphological design and heterojunction fabrication. The C-doping significantly promotes the visible light response and charge migration of g-C 3 N 4 , thus benefiting to the removal of DOX. Meanwhile, the 0D/3D heterogeneous morphology endows the catalysts with abundant active sites, high adsorptive capacity, favourable structural stability, high surface area and enhanced charge migration, which all contribute to the excellent adsorption and photocatalytic performance. The superoxide radicals shown a prominent role in the photocatalytic reaction. In addition, the Toxicity Estimation Software Tool, liquid chromatography-mass spectrometry and density functional theory calculations were also employed to investigate the DOX degradation mechanism, possible pathways and corresponding toxicity of intermediates. This work provides a promising way to develop highly efficient catalysts for the degradation of DOX.
研究领域:
环境科学
·
材料科学
·
毒理学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Mingmei Zhang,Zhiye Huang,Junjie Jiang,Weitong Zhou,Woyuan Li,Jimin Xie,Zonggui Hu,Zhonghua Wang,Zaoxue Yan
A novel and hierarchical porous but cross-linked copper-doped biomass graphene (Cu@HPBG) combined with Nb 2 O 5 (denoted as Nb 2 O 5 /Cu@HPBG) is successfully fabricated on a large-scale using fig peels as biomass carbon and copper as the graphitization catalyst. During the synthesis process, basic copper carbonate serves dual functions of pore-forming agent, as well as homogeneous copper provider, and NH 3 is employed as a defect-forming agent and N dopant. Owing to the porous hierarchical structure increased availability of contact interface and pseudo capacitance active sites provided by copper and Nb 2 O 5 , the assembled asymmetrical supercapacitor (ASC) employing Nb 2 O 5 /Cu@HPBG as positive electrode and HPBG as negative electrode can not only widen the stability window range of 0～1.9 V, but also deliver a maximum gravimetric energy density of 82.8 W h kg −1 at the power density of 950.0 W kg −1 and maintain a remarkable cycling stability of 97.1% after 15,000 cycles. Impressively, due to the synergistic enhancement of Cu@HPBG and Nb 2 O 5 , the resulting Nb 2 O 5 /Cu@HPBG hybrid displays more positive half wave potential (∼0.85 V) and a long-life stability than Pt/C electrode toward oxygen reduction reaction (ORR). Our research provides a feasible strategy to fabricate renewable biomass graphene electroactive composites for large-scale supercapacitor electrodes and efficient ORR catalysts toward energy applications.
研究领域:
材料科学
·
能源技术
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 25
·14534-14544
·
IF 12.732
Fei Shen,Zhongti Sun,Liang Zhao,Yuanhua Xia,Yanyan Shao,Jingsheng Cai,Shuo Li,Chen Lu,Xiaoling Tong,Yu Zhao,Jingyu Sun,Yuanlong Shao
Developing high energy density and high-power density electrode materials is of great importance for lithium-ion batteries to satisfy the requirements of the customer market. We report that introducing Mo into Nb2O5 at a low temperature leads to phase transition from bronze-phase T to crystallographic shear-phase H. The resulting Nb1Mo0.1O2.8 exhibits higher energy density than T-Nb2O5 and improved rate-performance and cycling-stability compared to H-Nb2O5. Neutron diffraction was applied to Nb1Mo0.1O2.8 to characterize the structure and two-phase ratios of the mixed metal oxide together with the first-principles method to calculate the possible Mo substitution sites. The Nb1Mo0.1O2.8 anode displays intrinsic pseudocapacitive lithium-ion intercalation with a high energy density of 362 mA h g−1 at 0.2C. In situ XRD results suggest that Nb1Mo0.1O2.8 is able to intercalate more lithium ions with smaller structure expansion compared with H-Nb2O5; furthermore, a computational method reveals that the introduction of Mo into the oxide increases Li atom adsorption energies and decreases the diffusion barrier. Therefore, Nb1Mo0.1O2.8 is a promising anode material for high-capacity and high-rate lithium-ion energy storage.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Xiaobo Ding,Huiying Huang,Qianhui Huang,Benrui Hu,Xiaokang Li,Xiangdong Ma,Xunhui Xiong
Heteroatoms doping has been regarded as a promising route to modulate the physiochemical properties of electrode materials, in which the doping sites greatly influence the electrochemical performances. However, very few reports focus on enhancing the lithium storage performances of Nb 2 O 5 via heteroatoms doping, yet the effect of different doping sites remains unclear. Herein, nitrogen doping has been proposed to improve the fast-charging capability of orthorhombic Nb 2 O 5 (T-Nb 2 O 5 ) via a urea-assisted annealing process . Experimental data and theoretical calculation demonstrate that the N doping sites in T-Nb 2 O 5 can be tuned by the heating rate , in which substitutional N can increase the spacing of the Li + transport layer as well as reduce the band gap, while interstitial N can provide an electron-rich environment for Li + transport layer and then reduce the Li + diffusion barrier . Arising from the synergistic effect of N doping at different sites, the N-doped T-Nb 2 O 5 without carbon coating delivers impressive rate performance (104.6 mA h g −1 at 25 C) as well as enhanced cycle stability with a retention of 70.5% over 1000 cycles at 5 C. In addition, the assembled lithium ion capacitor exhibits a high energy density of 46.6 Wh kg −1 even at high power density of 8.4 kW kg −1 .
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jiamei Lai,Chunhai Jiang,Zhimin Zou
Nanosized oxygen-deficient orthorhombic niobium pentoxide (Nb 2 O 5-x ) that possess high electronic conductivity and stable cycle performance for Li storage are uniformly deposited on the surface of mesophase carbon microspheres (MCMB), which as a whole exhibits very encouraging electrochemical Li ion storage performance, including a high specific capacity of 107 mAh g −1 at 10C (1C = 372 mA g −1 ) and a high capacity retention of 85.4 % after 300 cycles at 3C in the optimized case. The Li + diffusion coefficient of the composite anode as determined by the potentiostatic intermittent titration technique (PITT) is obviously improved as compared to that of pristine MCMB. Ex situ X-ray diffraction characterizations confirm the phase transformation from orthorhombic Nb 2 O 5-x to amorphous Li y Nb 2 O 5-x accompanied by the formation of NbO through a conversion reaction in the first lithiation process. The ultrafast Li + diffusion within the amorphous Li y Nb 2 O 5-x as well as the current-sharing effect of the secondary particles can explain the much enhanced Li ion storage property. The results of this work convincingly demonstrate that designing MCMB/Nb 2 O 5-x composite can be a more practical way to improve the energy and powder densities of Li-ion batteries rather than seeking alternative anode materials with higher capacities.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 85
·45088-45094
·
IF 3.708
Zhenwei Zhang,Fei Wang,Chuanling Chen,Tao Zhang,Xingmao Jiang,Zhi Yun
A facile soft chemistry route was described to prepare a composite material of Nb2O5 nanowires modified with Pd nanoparticles having an average diameter of 7.9 nm. The Pd/w-Nb2O5 catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS) techniques. In comparison with Pd/s-Nb2O5 and Pd/Al2O3, the Pd/w-Nb2O5 had a more substantial catalysis effect on the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) under ambient conditions. The results showed that the conversion rate of 4-NP (20 mg L−1, 100 mL) was about 98.3% after 4 min using 10 mg of the catalyst, Moreover, after the catalyst had been reused 10 times, the conversion rate still remained 85.3%. The significant enhancement in the catalysis activity can be ascribed to acidity and morphology of the catalyst support Nb2O5.
研究领域:
催化
·
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Nanzhu Nie,Dan Zhang,Zuochao Wang,Wenhao Yu,Shijie Ge,Juan Xiong,Yanli Gu,Bo Yang,Jianping Lai,Lei Wang
Powerful, efficient, and corrosion-resistant electrocatalysts are in need to achieve high-current-density neutral seawater hydrogen evolution. Here, a novel strategy through strong metal-support interaction (SMSI) and incorporation of Pt to construct PtNb-Nb 2 O 5 clusters @C was developed with stable high-current-density neutral seawater hydrogen evolution property for the first time. SMSI prevents agglomeration and corrosion of nanomaterials. Pt sites were proposed to play an anabranch role by binding H* to stabilize the Nb valence state and prevent water dissociation incapacitation. The optimized PtNb-Nb 2 O 5 @CC delivers low overpotentials of 440 mV (500 mA cm −2 ) and 570 mV (1000 mA cm −2 ) in neutral seawater and has 360 h excellent durability at 500 mA cm −2 . In-situ Fourier transform infrared spectroscopy (FTIR), in-situ Raman spectroscopies and theoretical calculations supported the hydrogen evolution reaction (HER) mechanism. PtNb-Nb 2 O 5 heterogeneous interface provided more active sites for water dissociation. OH* adsorbed on Nb sites in stable Nb 2 O 5 , and H* adsorbed on Nb sites and desorbed as H 2 on Pt sites in stable PtNb. Overall, this work not only first achieves stable high-current-density neutral seawater hydrogen evolution property, but also opens a new opportunity to explore SMSI and incorporation of Pt to prevent agglomeration, corrosion, and water dissociation incapacitation for catalytic applications under high current densities.
研究领域:
材料科学
·
电化学
·
可再生能源
·
催化
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Shitong Yu,Pan Xu,Zhicheng Luo
Converting lignin into renewable fuels via hydrogenolysis is crucial for achieving carbon neutrality. Existing methods primarily produce monomers in the carbon range of 6–9, inadequate for sustainable aviation fuels requiring heavier components. This study introduces a Ni/Nb 2 O 5 catalyst for catalytic transfer hydrogenolysis of organosolv birch lignin with isopropanol, predominantly resulting in dimers and trimers within carbon ranges of 8–16 and 16–30, comprising 24.7 % and 60.5 % of the lignin-oil, respectively. The catalyst's oxygen vacancies and acid sites facilitate efficient C-O and C-C bonds cleavage, preserving a highly aromatic structure with reduced O/C ratio, elevated H/C ratio, and decreased unsaturation. Characterization techniques confirm a significant 55.5 % deoxygenation degree of the lignin-oil, making it suitable for the synthesis of customized fuel across various carbon numbers. This approach offers a practical pathway for obtaining renewable heavier fuel components and precursors from lignin, significantly advancing sustainable fuel technologies.
研究领域:
化学工程
·
可再生能源
·
催化
·
可持续燃料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）