MICROPOROUS AND MESOPOROUS MATERIALS
·
2013
·
IF 3.365
Lan-Lan Lou,Huanling Du,Yanbin Shen,Kai Yu,Wenjun Yu,Qiu Chen,Shuangxi Liu
Chiral 9-amino epi -cinchonine was anchored on external surface passivated SBA-15 as well as calcined SBA-15. The two resulting materials were used as catalysts for the asymmetric transfer hydrogenation of aromatic ketones after complexing with [Ir(COD)Cl] 2 . Higher enantioselectivities were obtained over the passivated SBA-15 supported catalyst compared with the catalyst based on calcined SBA-15 as well as the homogeneous counterpart. Especially for the substrate of acetophenone, an obviously high enantiomeric excess (ee) of 74% (homogeneous ee: 60%) was achieved with comparable conversion to the homogeneous catalyst (97% vs. 98%). Furthermore, the passivated SBA-15 supported catalyst demonstrated higher stability during the asymmetric transfer hydrogenation reaction as compared with the catalyst based on calcined SBA-15.
研究领域:
催化化学
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有机合成
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材料化学
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纳米材料
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均相与多相催化
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DOI
高影响因子
ACS Applied Energy Materials
·
2026
·
IF 5.5
Yi Cao,Hao Ren,Tianjiao Ling,Junli Zhu,Yuanyuan Zhang,Lan Hong,Minqi Sheng
Precious metal-based catalysts exhibit superior performance over non-precious metal-based counterparts in acidic water splitting due to their relatively high corrosion resistance. However, their catalytic performance, especially in terms of mass activity and durability, is yet to be improved to meet commercial requirements. Herein, ultrathin porous Ir−Co−P alloy nanosheets (∼2.14 nm thick) with abundant grain boundaries, denoted as Ir−Co−P 340, were successfully synthesized via a KOH-assisted calcination and sequent phosphidation. The distinctive two-dimensional morphology exposes more surface atoms, shortens charge diffusion distances, and induces strong physical repulsion to prevent aggregation, while numerous pores facilitate efficient electrolyte penetration. The abundant grain boundaries not only proliferate active sites but also stabilize microstructures through a pinning effect. Dual alloying with Co and P enhances intrinsic catalytic activity and conductivity while reducing the cost of the catalyst. As a bifunctional catalyst in 0.5 M H2SO4 solution, Ir−Co−P 340 exhibited remarkable precious metal mass activities of 11.09 A mgIr−1 (HER, −0.03 Vvs.RHE) and 2.56 A mgIr−1 (OER, 1.26 Vvs.RHE), approximately 2.04 and 8.5 times higher than those of Pt/C and rutile-IrO2, respectively. A symmetric PEM electrolysis cell (Ir−Co−P 340||Ir−Co−P 340) delivered an ultralow cell voltage of 1.49 V at 10 mA cm−2 and outstanding durability over 200 h at a high current density of 50 mA cm−2.
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JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Dan Du,Zhirong Qu,Weiwei Zhang,Hong Dong,Chuan Wu
The density, viscosity and speed of sound of trimethoxylsilane derivatives with ethanol, 1-butanol, 1-pentanol and 1-octanol have been measured at 298.15, 303.15, 308.15, 313.15 K, 318.15 and 323.15 K, respectively. The excess molar volume, viscosity deviation, excess Gibbs energy of activation of viscous flow, isobaric thermal expansivity and isentropic compressibility deviation were calculated from these results. The Redlich–Kister equation was used for the correlation. The calculated excess properties have been discussed according to the possible interactions formed between the molecules in the mixture using equimolar attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. In all of the compositions and experimental temperature ranges studied, the excess molar volumes were found to be negative for vinyl trimethoxy silane and phenyl trimethoxy silane with ethanol. This may be attributed to the close accumulation of molecules and easier formation of cross-association structures between the alkoxysilane molecules. However, the excess molar volume of the binary mixture of vinyl trimethoxy silane and phenyl trimethoxy silane with n -butanol, n -pentanol, and n -octanol was positive. Hydrogen bond fracture may play a leading role in this process. The excess molar volumes of the binary system comprised of trifluoropropyl trimethoxy silane with ethanol and 1-octanol were all positive. This may be attributed to the influence of steric hindrance, which makes it difficult for trifluoropropyl trimethoxy silane to form a cross-association structure with alcohol molecules.
研究领域:
物理化学
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材料科学
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DOI
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Rongying Zhu,Renqin Yu,Kun Yin,Shiming Zhang,Joey Chung-Yen Jung,Yufeng Zhao,Menggang Li,Zhonghong Xia,Jiujun Zhang
Developing highly active methanol oxidation electrocatalysts with superior anti-CO poisoning capability remains a grand challenge. Herein, a simple strategy was employed to prepare distinctive PtFeIr jagged nanowires with Ir located at the shell and Pt/Fe located at the core. The Pt 64 Fe 20 Ir 16 jagged nanowire possesses an optimal mass activity of 2.13 A mg Pt -1 and specific activity of 4.25 mA cm −2 , giving the catalyst a great edge over PtFe jagged nanowire (1.63 A mg Pt -1 and 3.75 mA cm −2 ) and Pt/C (0.38 A mg Pt -1 and 0.76 mA cm −2 ). The in-situ Fourier transform infrared (FTIR) spectroscopy and differential electrochemical mass spectrometry (DEMS) unravel the origin of extraordinary CO tolerance in terms of key reaction intermediates in the non-CO pathway. Density functional theory (DFT) calculations add to the body of evidence that the surface Ir incorporation transforms the selectivity from CO pathway to non-CO pathway. Meanwhile, the presence of Ir serves to optimize surface electronic structure with weakened CO binding strength. We believe this work will advance the understanding of methanol oxidation catalytic mechanism and provide some insight into structural design of efficient electrocatalysts.
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DOI
PubMed
高影响因子
Catalysts
·
2023
·Vol. 13
·期 2
·322
·
IF 3.9
Kai Che,Xiaoyang Zhu,Guangshi Tang,Man Zhao,Junqing Pan
The hydrometallurgical technology provides an efficient and sustainable green lead recovery process from lead acid batteries. Methanesulfonic acid has been widely considered as a green solvent for lead electrolytic recovery. However, the competitive precipitation of PbO2at anode and higher overpotential for OER limit the lead recovery efficiency. In this work, an anodic oxygen evolution reaction (OER) catalyst with a low Ir mass fraction of 7.2% is obtained by electroplating iridium on carbon cloth (CC), exhibiting a lower overpotential of 256 mV, longer lifetime of 10 h, and better stability in the 0.5 M MSA solution. When CC-Ir is used as an anodic catalyst for lead recovery in the lead methanesulfonate electrolyte, only a lesser Pb precipitation product with Pb atom mass fraction of 1.42% is found after electrolysis of 10 h, demonstrating the suppression effect of CC-Ir for a PbO2side reaction. This work proves that the anodic catalyst plays an important role in the lead electrolytic recovery process, which can inhibit the side reaction, reduce the energy consumption, and increase recovery efficiency.Keywords:oxygen evolution reaction;noble metal catalyst;electroplating;lead methanesulfonate
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INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 13
·19221-19232
·
IF 4.672
Vi Thuy Thi Phan,Toan Minh Pham,Hau Quoc Pham,Tai Thien Huynh,Thi Hong Tham Nguyen,Van Thi Thanh Ho
Summary Highly stable and cost-effective electrocatalysts are of importance in regulating energy conversion efficiency and commercial feasibility of direct methanol fuel cells (DMFCs). So far, integrating transition metals into Pt-based catalysts to enhance their catalytic performances for methanol electro-oxidation reaction (MOR) at the anode of DMFCs has received significant interest. This study witnessed the first time of depositing Pt 3 Co 1 alloy nanoparticles (NPs) on robust Ti 0.9 Ir 0.1 O 2 supports utilizing a modified reduction method that used NaBH 4 as a reducing agent in the absence of surfactants or stabilizers. This novel combination not only reduces the usage of costly and easily-deactivated Pt but also significantly improves catalytic activity and poisoning tolerance for MOR. Regarding electrocatalytic performance, the onset potential and the mass activity of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are ~0.1 V vs NHE and 316.16 mA/mg Pt , respectively, which are 4.5-fold lower and 1.5-fold higher than the corresponding figures for the commercial Pt/C (E-TEK) catalyst, ~0.45 vs NHE and 206.83 mA/mg Pt , indicating superior catalytic activity and CO-tolerance of the former over the latter. Furthermore, the superior anti-poisoning ability and stability of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are demonstrated by its 2.2-fold higher I f /I b ratio in MOR and lower degradation rate in the 60-min chronoamperometry (CA) and 3000-cycle scanning tests than the Pt/C counterpart. These enhancements could be abscribed to synergistic influence between the Pt-Co alloy NPs and the robust Ti 0.9 Ir 0.1 O 2 support. The addition of Co into the catalyst to promote removal of Pt-poisoning species as well as the use of highly corrosion-resistant Ir-doped TiO 2 as a catalyst support play a decisive role in boosting electrochemical behaviors of the Pt 3 Co 1 / Ti 0.9 Ir 0.1 O 2 catalyst. Generally, the success of this work in synthesizing high-performance Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst could serve as groundwork for further development of TiO 2 -based material supported bimetallic catalysts for applications in the electrochemical catalysis field.
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ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Yitian Huang,Dandan Zhao,Yanjie Chen,Shupei Zhang,Feng Lin,Hong Dai
Iridium (Ir) complexes have gained remarkable development momentum as candidates for electrochemiluminescence , but their poor solubility in water media greatly limited their application in ECL area. Herein, a facile nanoprecipitation method by encapsulating tris(2-phenylpyridinato)iridium (Ir(ppy) 3 ) into pluronic block copolymers for preparing water-soluble Ir(III) complexes with high ECL emission efficiency was developed. Then, with F-127@Ir(ppy) 3 as the anode emitter and g-C 3 N 4 as the cathode emitter, a new ratiometric biosensor based on transition metal complexes was developed for the first time, which was used for ultra-sensitive detection of hepatitis C virus E2 protein. Notably, the ratiometric ECL signal could be mediated by using multifunctional Nb 2 C nanosheets (Nb 2 C NSs) with excellent electrocatalytic activity and superoxide dismutase activity, so as to enhance the ECL intensity of anode and quench the response of cathode ECL. Combining Nb 2 C NSs with the antibody and the specific recognition process, the proposed ECL ratio biosensor showed good performance for E2 with a linear range from 1 × 10 −3 ng/mL to 1 × 10 2 ng/mL and a detection limit of 8.39 × 10 −4 ng/mL. The work on designing water-soluble Ir (III) complexes with pluronic block copolymer provides an ingenious approach to broaden the application of poorly soluble complexes in bioassays.
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RSC Advances
·
2022
·Vol. 12
·期 22
·13660-13672
·
IF 4.036
Xiaofan Zhang,Ming Gao,Tingting Liu,Huili Wang,Xuedong Wang
Herein, we fabricated three imidazolium-based polymeric ionic liquids (PILs) with different anions (P[VEIM]BF4, P[VEIM]PF6 and P[VEIM]Br), and analyzed their differential extraction efficiencies for bifenthrin through H-bonding induced effects. Three PILs all presented an irregular block structure with rough surface and lower specific-surface area (SSA, 11.2–18.7 m2 g−1) than carbon-based nanomaterials. They formed hydrogen bonds with free-water molecules in the lattice of PILs, including C2,4,5–H⋯O–H, Br⋯H–O–H⋯Br, O–H⋯Br, C2,4,5–H⋯F–P, P–F⋯H–O–H⋯F–P, C2,4,5–H⋯F–B and B–F⋯H–O–H⋯F–B. After extraction, the O–H stretching-vibration peak was prominently intensified, whereas the C–H bond varied slightly concomitant with reduced B–F and P–F vibration. Theoretically, the C–H vibration should become more intense in the C4,5–H⋯H2O and C2–H⋯H2O bonds after extraction in contrast to before extraction. These contrary spectral changes demonstrated that the hydrogen bonds between cations in the PILs and free-water molecules were broken after extraction, yielding the H-bonding occurrence between bifenthrin and H–O–H in the lattice. As a time indicator for the free-water binding and releasing process, the highest slope for the plot of It/I0 against time implied that the shortest time was required for P[VEIM]PF6 to reach an adsorption equilibrium. Overall, the strong hydrophobicity, small SSA and electrostatic-repulsion force for P[VEIM]PF6 are all not conducive to its efficient adsorption. Beyond our anticipation, P[VEIM]PF6 provided the highest extraction recovery for bifenthrin up to 92.4% among three PILs. Therefore, these data lead us to posit that the above high efficiency results from the strongest H-bonding effect between P[VEIM]PF6 and bifenthrin. These findings promote our deep understanding of PILs-triggered differential efficiency through a H-bonding induced effect.
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PubMed
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 15
·2106120
·
IF 17.521
Peng Wang,Yu Chu,Abudukadi Tudi,Congwei Xie,Zhihua Yang,Shilie Pan,Junjie Li
Design and fabrication of new infrared (IR) nonlinear optical (NLO) materials with balanced properties are urgently needed since commercial chalcopyrite-like (CL) NLO crystals are suffering from their intrinsic drawbacks. Herein, the first defect-CL (DCL) alkali-earth metal (AEM) selenide IR NLO material, DCL-MgGa 2 Se 4 , has been rationally designed and fabricated by a structure prediction and experiment combined strategy. The introduction of AEM tetrahedral unit MgSe 4 effectively widens the band gap of DCL compounds. The title compound exhibits a wide band gap of 2.96 eV, resulting in a high laser induced damage threshold (LIDT) of ≈3.0 × AgGaS 2 (AGS). Furthermore, the compound shows a suitable second harmonic generation (SHG) response (≈0.9 × AGS) with a type-I phase-matching (PM) behavior and a wide IR transparent range. The results indicate that DCL-MgGa 2 Se 4 is a promising mid-to-far IR NLO material and give some insights into the design of new CL compound with outstanding IR NLO properties based on the AEM tetrahedra and the structure predication and experiment combined strategy.
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PubMed
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ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
·
2022
·Vol. 47
·期 6
·7123-7134
·
IF 2.807
Wang Pengjie,Xiong Liping,He Zhongyi,Xu Xin,Hu Jianqiang,Chen Qi,Zhang Renhui,Pu Jibin,Guo Lei
The corrosion inhibition effect and synergistic mechanism of novel imidazoline derivative (SMIF) and benzimidazole (BMZ) in 3.5 wt% simulated concrete solution were studied experimentally and theoretically. The complex inhibitors have the most outstanding inhibition efficiency when SMIF concentration is 0.1 g/L and BMZ is 0.9 g/L, the corrosion inhibition efficiencies of weight loss, Electrochemical Impedance Spectroscopy and Potentiodynamic polarization curve (Tafel) were 88.81%, 86.27% and 90.22%, respectively. Electrochemistry analysis results proved that the corrosion inhibition mechanism of the inhibitors in the corrosion solution was mainly the formation of a protective film on the surface of carbon steel. FT-IR, Energy Dispersive Spectroscopy and X-ray Photoelectron Spectroscopy all proved the existence of the protective film. Molecular dynamics proved that the composite inhibitor molecules could be stable on the surface of carbon steel and when consist of complex inhibitor was 0.1 g/L SMIF and 0.9 g/L BMZ the stable adsorption morphology were the highest. This work confirmed that SMIF and BMZ inhibitors have a good synergistic effect, greatly improving the inhibition efficiency and reducing the cost of corrosion inhibition, and has a certain guiding significance for synergistic inhibition.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Junfei Chen,Xuyu Wang,Liling Zhang,Zebao Rui
Skillful arrangement of the active sites with stable dispersion and desired chemical states on the support surface is vital for their powerful application in catalysis, but remains a daunting challenge. Herein, we present a unique redispersion strategy for well dispersing and stabilizing IrO 2 /Ir active sites over TiO 2 as an advanced catalyst for low temperature CH 4 oxidation. The as-designed Ir/TiO 2 with a 1 wt.% Ir loading amount exhibits a (>)99 % CH 4 conversion and excellent durability at a temperature as low as 320 °C, which ranges among the best of state-of-the-art methane combustion catalysts. Various characterizations and DFT calculations were performed to reveal the redispersion mechanism and understand the reason for the enhanced performance. The superior performance is related to the proper chemical state of complex IrO 2 /Ir active sites and their ultrafine and stable dispersion, all relating to the strong metal-support interaction (SMSI) induced redispersion process. Such SMSI assisted active sites redispersion strategy provides useful guidance for the rational design of efficient Ir-based and other noble metal catalysts.
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Qiannan Pan,Jun Xie,Ling Lin,Miao-Si Hong,Xi-Chang Wang,Su-Qin Sun,Chang-Hua Xu
Fluorescent brighteners, illegally used to whitening wheat flour, are detrimental to people health. The aim was to establish a rapid and direct method to identify and quantify fluorescent whitening agent OB-1 (FWA OB-1) in wheat flour by using multi-molecular infrared (MM-IR) spectroscopy combined with stereomicroscopy. Characteristic peak profile of FWA OB-1 used as a judgment basis was spatially revealed by stereomicroscopy with group-peak matching of MM-IR at 1614 cm −1 , 1501 cm −1 and 893 cm −1 and were further unveiled by the second derivative infrared spectroscopy (SD-IR) and its two-dimensional correlation infrared (SD-2DCOS IR) spectroscopy for higher resolution, and were validated by high-performance liquid chromatography (HPLC). Moreover, a quantitative prediction model based on IR spectra was established by partial least squares 1 (PLS1) (R 2 , 98.361; SEE, 5.032; SEP, 5.581). The developed method was applicable for rapid and direct analysis of FWA OB-1 (low to 10 ppm) in flour with relative standard deviation (RSD) of 5%. The capabilities of MM-IR with spectral qualitative and quantitative analysis would be applicable to direct identification and quantitation of fluorescent whitening agents or other IR-active compounds in powder objects.
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高影响因子
危险品化学品经营许可证（带存储）