CATALYSIS LETTERS
·
2018
·Vol. 148
·期 11
·3492-3501
·
IF 2.911
Wang Xueyuan,Chen Li,Huang Deqi,Yue Jinfang,Luo Zhichen,Zeng Tao
Abstract The views on catalytic activity of zeolite in isomerization of α -pinene have not came to an agreement. Thus, the key active substance in zeolite was further studied through experiments. H-mordenite was treated in three ways: (i) calcination under nitrogen flows, (ii) calcination under oxygen flows, (iii) calcination under nitrogen flows after alkali treatment. The properties of modified zeolites were investigated by methods of SEM, EDS, XRD, nitrogen adsorption, NH 3 -TPD, Py-IR, and 29 Si and 27 Al MAS NMR. The results showed that the zeolites produced mesoporous after 0.4M NaOH solution soaking and calcinations above 500 °C, but it had a slight effect on the change of micropore volumes. Comparison of zeolite acid sites amount under different roasting temperature by NH 3 -TPD showed that the decrease of acid sites amount was mainly related to the roasting temperature. Py-IR and 27 Al MAS NMR experiment revealed that Lewis acid was produced by framework aluminum. Finally, Analysis on the influencing factors we studied of H-mordenite catalytic activity in this paper suggested that, in isomerization of α -pinene, the relative concentration of six-coordination aluminum in zeolite is the dominant factor of provided catalytic activity of H-mordenite. Graphical abstract
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CATALYSIS TODAY
·
2018
·
IF 4.667
Lingcong Li,Xiaojun Liu,Hong He,Ningqiang Zhang,Ziwen Liu,Guizhen Zhang
The MgO-doped hexagonal boron nitride (MgO-h-BN) nanomaterials were designed as a support for Palladium (Pd) catalysts for CO oxidation reaction. The catalytic properties of Pd/MgO(5)-h-BN catalyst was investigated and compared with Pd/h-BN catalyst. Transmission electron microscopy (TEM) results suggested that the PdO nanoparticles with small grain sizes (ca. 8 nm) were effectively dispersed on the surface of MgO, and the MgO were deposited on the h-BN nanosheets in the Pd/MgO(5)-h-BN catalyst. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that a small amount of Mg 2+ embedded into the B vacancies of h-BN nanosheets in the Pd/MgO(5)-h-BN catalyst. More significantly, a large amount of adsorbed oxygen appeared near the B vacancies of Pd/MgO(5)-h-BN catalyst. The experiments outcomes of diffuse reflectance fourier transform spectra analysis of CO (CO-DRIFT) indicated that the carbonate/formate species were easily decomposed to CO 2 on the Pd/MgO(5)-h-BN catalyst than Pd/h-BN catalyst, which might be a reason why the Pd/MgO(5)-h-BN catalyst had high CO oxidation activity. According to above analyses, we provide a new insight for the MgO-h-BN nanomaterials for Pd catalysts for application in CO oxidation reaction.
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INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS
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2017
·
IF 4.307
Hong-Yan Luo,Ma-Feng Liu,Ming-Shu Wang,Xin-Xin Zhao,Ren-Yong Jia,Shun Chen,Kun-Feng Sun,Qiao Yang,Ying Wu,Xiao-Yue Chen,Francis Biville,Yuan-Feng Zou,Bo Jing,An-Chun Cheng,De-Kang Zhu
The Gram-negative bacterium Riemerella anatipestifer CH-2 is resistant to lincosamides, having a lincomycin (LCM) minimum inhibitory concentration (MIC) of 128 µg/mL. The G148_1775 gene of R. anatipestifer CH-2, designated lnu (H), encodes a 260-amino acid protein with ≤41% identity to other reported lincosamide nucleotidylyltransferases. Escherichia coli Rosetta TM (DE3) containing the pBAD24- lnu (H) plasmid showed four- and two-fold increases in the MICs of LCM and clindamycin (CLI), respectively. A kinetic assay of the purified Lnu(H) enzyme for LCM and CLI showed that the protein could inactive lincosamides. Mass spectrometry analysis demonstrated that the Lnu(H) enzyme catalysed adenylylation of lincosamides. In addition, an lnu (H) gene deletion strain exhibited 512- and 32-fold decreases in LCM and CLI MICs, respectively. The wild-type level of lincosamide resistance could be restored by complementation with a shuttle plasmid carrying the lnu (H) gene. The transformant R. anatipestifer ATCC 11845 [ lnu (H)] acquired by natural transformation also exhibited high-level lincosamide resistance. Moreover, among 175 R. anatipestifer field isolates, 56 (32.0%) were positive for the lnu (H) gene by PCR. In conclusion, Lnu(H) is a novel lincosamide nucleotidylyltransferase that inactivates LCM and CLI by nucleotidylylation, thus conferring high-level lincosamide resistance to R. anatipestifer CH-2.
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JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xu Yin,Jiatian Yu,Zhifeng Gao,Wei Li,Kajia Wei,Yun Jiang,Yonghao Zhang,Haoming Chen,Weiqing Han
Bromate (BrO 3 – ) is a common by-product of advanced oxidation water treatment processes. In this study, a catalyst combining MXene and Pd was synthesized to eliminate BrO 3 – by electrochemical reduction in flow-through mode. The fabricated Ti/Pd@MXene filter showed superior activity for BrO 3 – reduction compared with Ti/MXene filter. A satisfactory BrO 3 − removal performance by Ti/Pd@MXene filter was obtained at pH values of 5–7 with a current density of 1.0–2.5 mA·cm –2 . The mechanism explored by quenching experiments and EPR analysis demonstrated that atomic hydrogen (H*)-mediated reduction was dominant in the Ti/Pd@MXene filter system and contributed to 84.2 % of the BrO 3 − removal, which was greater than that of Ti (7.1 %) and Ti/MXene (43.9 %). DFT calculations revealed the introduction of Pd nanoparticles on MXene lowered the energy barrier for generating H* from OH* -H* , thus boosting H* formation. Furthermore, the Ti/Pd@MXene filter had favorable stability and applicability, and nearly 90 % of BrO 3 − could be eliminated in different water matrices. Moreover, energy consumption of the Ti/Pd@MXene filter was more competitive than that previously reported (0.348 kWh·mmol −1 ), especially for high BrO 3 − removal (≥75 %). This work highlighted an effective flow-through electrocatalytic filter to induce H* -mediated electrochemical reduction of BrO 3 − .
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Journal of Materials Chemistry A
·
2024
·
IF 10.7
Yuhui Huang,Yehan Tao,Qingqing Wang,Jian Du,Jinwen Hu,Jie Lu,Yanna Lv,Haisong Wang
To develop an industrial zeolite-based catalyst for efficient furfural production, the acidity, pore structure, and electronic properties of H-β zeolite were modulated by synergistic deatomization and atomic implantation treatments. The dealumination effectively decreased the intrinsic aluminum-related Lewis and Brosted acid sites, thus decreasing the occurrence of unwanted side reactions. Meanwhile, the removed skeleton aluminum can create voids for the following atomic implantation of introducing higher valent-state niobium species, which would provide new kinds of catalytic active sites, increase the average pore size by distorting the zeolite skeleton, and enhance the interaction with reactant molecules by acting as more electron deficient centers. In a single-phase water/γ-valerolactone reaction system, the optimum catalyst can efficiently convert both xylan and xylose with a conversion of 100 % at a medium temperature of 130 ℃ within 3 hours. Compared with the furfural yield over untreated H-β (12.7%), the yield over deAlβ/Nb(20%) catalyst was greatly enhanced by 54% with xylose as raw material. The catalyst can be recovered by simple cleaning and thermal regeneration and then reused. The proposed post-treatment strategy could maintain the integrity of the zeolite structure, ensure uniform and stable metal dispersion under harsh conditions, manage the complexity and cost of the preparation process, and most importantly, optimize the catalytic performance. Addressing these issues is essential for improving the efficiency and practical application of industrial zeolite catalysts by this general approach and benefiting industrial furfural production.
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ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Jingzhi Hu,Keyu Xie,Xiaoyan Liu,Shaohui Guo,Chao Shen,Xingrui Liu,Xuanhua Li,Jian-gan Wang,Bingqing Wei
A novel hexagonal boron nitride nanosheets (h-BN)-doped poly (vinyl alcohol)-sulfuric acid (PVA-H 2 SO 4 ) gel polymer electrolyte (GPE) is first fabricated through a facile freeze-thaw method. The ionic conductivities of the h-BN-doped PVA-H 2 SO 4 GPEs with various h-BN nanosheet contents are evaluated. With the optimal content of h-BN nanosheets (0.025 mg ml −1 ), the ionic conductivity of the GPE can reach up to 29 mS cm −1 , three times higher than that of GPE without the h-BN nanosheets (9 mS cm −1 ). The h-BN nanosheets are considered as a “super-highway” for ion transport in PVA-H 2 SO 4 GPE. Moreover, a symmetric qusai-solid-state supercapacitor, with activated carbon as electrodes and the h-BN nanosheets-doped PVA-H 2 SO 4 gel polymer as an electrolyte and separator, delivers a high specific capacitance, good rate capability, and excellent cycle stability. At the current density of 0.5 A g −1 , the symmetry qusai-solid-state supercapacitor can deliver an electrode specific capacitance of 124.5 F g −1 , and remain 99.2% capacitance after 5000 charge-discharge cycles. The h-BN nanosheets-doped GPE, with superior performance and facile synthesis method, appears to be a promising candidate for high-performance qusai-solid-state supercapacitors and other electrochemical devices, such as rechargeable batteries, fuel cells. This work also sheds light on the possibility to use 2D materials in advanced GPE.
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Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 41
·8193-8199
·
IF 4.543
Haiyan Jia,Zhangjun Huang,Zhaofu Fei,Paul J. Dyson,Zhen Zheng,Xinling Wang
Dipole–dipole and hydrogen-bonding interaction reinforced (DHIR) hydrogels that demonstrate both excellent thermo-responsive volume change and high mechanical strength have been developed. Their thermo-responsive volume change originates from the balance between the temperature-sensitive reversible dipole–dipole and H-bonding interaction and an embedded super-hydrophilic component. By integrating these thermal responsive DHIR hydrogels with non-swelling polyurethane (PU) hydrogels, bilayered (DHIR-PU) thermomorphic actuators capable of shape transformation have been fabricated. The hybrid DHIR-PU hydrogels have a wide temperature window allowing dual-responsive actuations to be achieved. The new hydrogel-based actuators are highly attractive materials for a range of transformative applications in soft robotics, medical devices and advanced manufacturing.
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BIOMEDICAL CHROMATOGRAPHY
·
2014
·Vol. 29
·期 6
·860-868
·
IF 1.662
Xiaoping Zhang,Huiqing Lv,Zuguang Li,Kezhi Jiang,Maw-Rong Lee
Ficus pandurata H. aerial roots are used as a traditional Chinese medicine for the treatment of uarthritis, indigestion and hyperuricemia. However, the bioactive constituents responsible for the pharmacological effects of F . pandurata H. are unclear. A simple and efficient HPLC/QTOF-MS/MS (high-performance liquid chromatography/electrospray ionization with quadrupole time-of-flight tandem mass spectrometry) method was established to detect and identify active constituents in the n -butanol extract of F . pandurata H. aerial roots. Chemical constituents were separated and investigated by HPLC/QTOF-MS/MS in the negative-ion mode. Thirty-seven compounds, including hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, hydroquinone glycosides, flavonoid glycosides, etc., were identified or tentatively characterized in the n -butanol extract of F . pandurata H. aerial roots by comparing the UV spectra, accurate mass spectra and fragmentation pathways and retrieving the reference literatures. Moreover, the flavonoid trisaccharides and hydroxybenzoic acid derivatives were tentatively characterized in F . pandurata H. for the first time. The analytical tool used here is very valuable in the rapid separation and identification of the multiple and minor constituents in the n -butanol extract of F . pandurata H. aerial roots. Copyright © 2014 John Wiley & Sons, Ltd.
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ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xiaoxiao Wang,Yanmei Yang,Zhiqing Zhou,Yuling Zhong,Miaomiao Qin,Weiqing Wang,Weifeng Li,Bo Tang
5-hydroxymethylfurfural (HMF) is one of the most promising biomass-based chemicals that is used to produce many kinds of important compounds. Especially, the selective conversion of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), an important chemical feedstock, has high industrial significance but is technically challenging. In this study, we present a high-performance photocatalyst for selective oxidation of HMF to HMFCA. By integrating an ultrasmall amount of palladium (Pd) nanoclusters (1.12‰ in weight) on defective hexagonal boron nitride nanosheets (Pd/defective h-BN nanosheets (dh-BNs)), outstanding photocatalytic performance can be achieved, resulting in up to a 95% HMF conversion ratio with an 82% HMFCA selectivity. The performance is considerably higher than that of pristine dh-BNs and Pd on defect-free h-BNs. More importantly, this Pd/dh-BNs catalyst maintains a high catalytic activity after eight cycles, demonstrating robust catalytic stability. Density functional theory calculations indicate that Pd/dh-BNs can lower the energy barrier for HMF oxidation and facilitate the desorption of HMFCA, which contributes to the high selectivity catalytic performance. This study not only introduces a promising photocatalyst for sustainable chemical transformations but can also provide valuable insights into the design of advanced photocatalytic material for biorefinery applications.
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Small
·
2025
·
IF 12.1
Ruiqi Guo,Shujuan Wang,Minqi Sheng,Xingli Zou,Mingzhi Zhang,Guangcheng Li,Yi Cao,Zhenglong Fan,Jinxin Chen,Wenxiang Zhu,Fan Liao,Tianjiao Ling,Hao Ren,Fan Lv,Zhenhui Kang
Iridium (Ir) is recognized to have extremely high catalytic activity in the hydrogen evolution reaction (HER). However, there are still technical challenges in maximizing the utilization of Ir atoms in the catalytic reaction process through dimensional regulation strategies. Herein, an innovative strategy is utilized to fabricate porous phosphorus-doped iridium (P-Ir) with a 2D structure, specifically the reduction of 1T phase-IrO 2 (1T-IrO 2 ) nanosheets using phosphine gas. The optimized P-Ir achieves an overpotential of 17.2 mV (vs RHE without i R-correction) in 0.5 m H 2 SO 4 during the HER process, outperforming benchmark Pt/C (27.0 mV) and most reported Ir-based electrocatalysts. During the long-term stability tests, P-Ir maintains stable operation for more than 100 h at both −10 and −100 mA cm −2 , respectively. Moreover, the HER activity and transient potential scanning results of Ir-based phosphides prove that doping P atoms in the Ir lattice promotes the reaction kinetic rate and charge transport capacity during hydrogen evolution. Theoretical calculations reveal that P atoms doping weakens the adsorption energy of H intermediates (H*) by regulating the d -band center of the Ir sites. Simultaneously, the desorption process of H* is also facilitated by forming a special bridged-H* bond structure, eventually accelerating the HER kinetics.
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CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Ruijie Ma,Huimin Gao,Jinpeng Zhang,Jieying Jing,Wen-Ying Li
Photocatalytic reduction of CO 2 to formic acid (HCOOH) offers a sustainable pathway for carbon utilization, yet its efficiency is fundamentally limited by poor CO 2 adsorption and rapid electron-hole recombination in conventional photocatalysts. To address this challenge, a series of Pd-loaded hydrogenated TiO 2 catalysts (x wt%Pd/H-TiO 2 ) were developed through a synergistic hydrogen reduction-impregnation strategy, aiming to regulate the electron density of Pd active sites and enhance interfacial charge separation. Systematic characterization revealed that increasing Pd loading (0.6–1.4 wt%) effectively trapped photogenerated electrons, suppressing recombination losses and elevating electron density at Pd sites. Combined with optimized CO 2 adsorption capacity (0.178 mmol·g −1 ) and accelerated charge transfer, the 1.0 wt%Pd/H-TiO 2 catalyst achieved a HCOOH production rate of 14.14 mmol·g cat −1 ·h −1 under mild conditions (30 °C, 2.0 MPa, 4.57 mW·cm −2 ), outperforming most reported TiO 2 -based systems. Mechanistic studies further demonstrated a strong correlation between Pd-induced electronic effects and multi-electron CO 2 activation kinetics. This work provides a scalable catalyst design paradigm for balancing charge dynamics and surface reactivity in photocatalytic CO 2 valorization.
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Nano-Micro Letters
·
2022
·Vol. 14
·期 1
·1-12
·
IF 23.655
Yang Peng,Zha Jiajia,Gao Guoyun,Zheng Long,Huang Haoxin,Xia Yunpeng,Xu Songcen,Xiong Tengfei,Zhang Zhuomin,Yang Zhengbao,Chen Ye,Ki Dong-Keun,Liou Juin J.,Liao Wugang,Tan Chaoliang
The growth of high-quality single-crystalline Te nanobelts is reported by introducing atomically flat hexagonal boron nitride (h-BN) nanoflakes into the chemical vapor deposition system as the growth substrate.
The field-effect transistor based on Te grown on h-BN exhibits an ultrahigh hole mobility up to 1370 cm 2 V −1 s −1 at room temperature.
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危险品化学品经营许可证（带存储）