CHINESE JOURNAL OF CATALYSIS
·
2018
·
IF 3.525
Zhou Ren,Yuan Lyu,Siquan Feng,Xiangen Song,Yunjie Ding
Highly active Ir-La-S/AC catalyst was successfully prepared by co-impregnation of an activated carbon (AC) carrier with a sulfuric acid solution of Ir and La species and compared with a traditionally prepared Ir-La/AC catalyst. High angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM) measurement results show that most of the Ir species on Ir-La-S/AC exist as single atomic sites, while those on Ir-La/AC exist as nanoparticles with an average diameter of 1.5 nm. Evaluation of Ir-La-S/AC as a catalyst for heterogeneous carbonylation of methanol to acetyl gave a maximum TOF (turn-over-frequency) of 2760 h −1 , which was distinctly higher than that achieved by the Ir-La/AC catalyst (approximately 1000 h −1 ). Temperature-programmed desorption of ammonia (NH 3 -TPD) result shows that the addition of sulfuric acid during the preparation procedure results in significantly more acidic sites on Ir-La-S/AC than those on Ir-La/AC, which plays a key role in the enhancement of CO insertion as the rate-determining step. Temperature-programmed reduction (TPR) and in situ X-ray photoelectron spectroscopy reveal that Ir species are more reducible, and that more Ir + might be formed by activation of Ir-La-S/AC than those on the Ir-La/AC catalyst, which is thought to be beneficial for reductive elimination of AcI from Ir 3+ species as an essential step for CH 3 I regeneration and acetyl formation.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2021
·Vol. 36
·期 3
·e9218
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IF 2.419
Mengying Du,Kailin Zhang,Luyang Jiao,Yicheng Xu,Xianglei Kong
Rationale The challenge of glycan identification due to their structural complexity and diversity has profited enormously from recent developments in mass spectrometry (MS)-related methods. For photodissociation MS, infrared (IR) and ultraviolet (UV) lasers can generate complementary fragment ions, so an effective combination of the two methods may provide rich and valuable fragmentation patterns for glycan analysis. Methods A 7.0 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer equipped with a double-beam laser system was applied for the experiments. 3,5-Diiodo-L-tyrosine was selected as the assistant molecule to form complex ions with ten isomeric disaccharides through electrospray ionization. The complex ions were further isolated and irradiated by IR and UV lasers separately or continuously in the FTICR cell. Results By combining the two complementary fragment spectra generated from the IR and UV lasers, a clear identification of all the ten isomers was achieved using their binary codes based on their fragmentation patterns. The double-beam method simplifies the experiment by introducing the two lasers sequentially in one experiment, providing richer fragmentation patterns and making the full discrimination easier. Conclusions This study demonstrates the capabilities of the combination of IR and UV photodissociation MS in the identification of diverse glycan isomers. The double-beam photodissociation method described here distinguished compositional, configurational and connectivity disaccharide isomers successfully. Compared with the data accumulation method based on separate IR and UV experiments, this method is simpler, faster, more flexible and also characterized by richer fragmentation patterns.
研究领域:
生物化学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemPhotoChem
·
2020
·Vol. 4
·期 5
·357-365
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IF 2.838
Huan Ling,Fengyu Su,Yanqing Tian,Dan Luo,Yan Jun Liu,Xiao Wei Sun
Graphical Solid as a rock : A simple acceptor-donor-acceptor structured viologen analogue 4, 4′-(thiophene-2, 5-diyl)bis(1-methylpyridin-1-ium) diiodide was synthesized and the corresponding all-in-one gel electrochromic device (ECD) was fabricated. High electrochromic performances including large contrasts (up to 81.7 % at 570 nm), excellent color efficiency (up to 228.8 cm 2 /C at 570 nm), and extremely high stability (up to 25000 cycles) were obtained. Finally, the absorption of visible-NIR light could be adjusted selectively by varying the coloring time. Energy saving is a global topic of critical importance. Electrochromic devices (ECDs) could be used to control energy flow by modulating the light absorption reversibly upon application of a small potential bias. Herein, a visible-NIR dual-band ECD based on the viologen analogue 4, 4′-(thiophene-2, 5-diyl) bis(1-methylpyridin-1-ium) diiodide (TMP) was assembled with a simple all-in-one configuration. The TMP-based gel ECD possesses high dynamic contrast (81.7 % at 570 nm, 68.6 % at 835 nm, 62.8 % at 910 nm and 55.3 % at 1046 nm), excellent cyclic stability (70.6 % of ▵T at 570 nm maintained after 25000 cycles at 1.4 V), and low power consumption (15.2 mJ/cm 2 to complete the coloring process, 2.5 mW/cm 2 to keep color and low transmittance). Remarkably, the absorption of visible and NIR light could be selectively adjusted by varying the coloring time. For comparison, a dimethyl viologen (DMV)-based gel ECD was fabricated, and the SAR (structure-activity relationship) was established by cyclic voltammetry, density functional theory (DFT) calculations, and other electrochromic performance parameters.
研究领域:
材料科学
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电化学
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光电子学
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能源材料
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2022
·Vol. 13
·期 1
·2202913
·
IF 29.698
Dan-Qing Liu,Zhouxin Luo,Bingxing Zhang,Guoqiang Zhao,Wei Guo,Jian Chen,Mingxia Gao,Yongfeng Liu,Hongge Pan,Wenping Sun
The sluggish kinetics of hydrogen oxidation reaction (HOR) is one of the critical challenges for anion exchange membrane fuel cells. Here, we report epitaxial growth of Ir nanoclusters (<2 nm) on a MoS 2 surface (Ir/MoS 2 ) and optimize the alkaline HOR activity via tailoring interfacial charge transfer between Ir clusters and MoS 2 . The electron transfer from MoS 2 to Ir clusters can effectively prevent the oxidation of Ir clusters, which is not the case for carbon-supported Ir nanoclusters (Ir/C) synthesized using the same method. Moreover, the HOR performance of the Ir/MoS 2 can be further optimized by tuning the hydrogen binding energy (HBE) via a precise annealing treatment. A substantial exchange current density of 1.28 mA cm ECSA −2 is achieved in the alkaline medium, which is ∼10 times over that of Ir/C. The HOR mass-specific activity of Ir/MoS 2 heterostructure is as high as 182 mA mg Ir −1 . The experimental results and density functional theory calculations reveal that the significant improved HOR activity is attributed to the decreased HBE, which highlights epitaxial growth is an effective way for boosting catalytic activity of heterostructured catalysts.
研究领域:
材料科学
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电化学
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催化
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燃料电池技术
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
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2023
·Vol. 10
·期 7
·2030-2038
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IF 7
He-Di Yang,Sheng-Hua Zhou,Mao-Yin Ran,Xin-Tao Wu,Hua Lin,Qi-Long Zhu
Transition-metal-based chalcogenides have recently emerged as greatly promising infrared nonlinear optical (IR-NLO) candidates due to their unique structural chemistries and rich optical properties. However, Fe-based IR-NLO chalcogenides with phase-matching (PM) features have not yet been reported. In this work, a new non-centrosymmetric (NCS) melilite oxychalcogenide, Sr2FeGe2OS6, has been prepared by an isomorphous substitution method, and the relationships between the microscopic crystal structure and macroscopic NLO activity were systematically investigated. Sr2FeGe2OS6 adopts the tetragonal space group of P21m (no. 113) and features a unique two-dimensional structure with Cairo pentagonal tiling layers formed by the alternating connection of [Ge2OS6] dimers and [FeS4] tetrahedra via corner-sharing and with the charge-balanced Sr2+ cations between these layers. Excitingly, Sr2FeGe2OS6 is the first Fe-based example capable of achieving PM in the IR-NLO chalcogenide system and displays an outstanding IR-NLO comprehensive performance, including a wide energy gap (Eg = 2.24 eV), sufficient second-harmonic-generation (SHG) efficiency (deff = 5.89 pm V−1 at 2050 nm) and strong laser-induced damage threshold (LIDT = 14.42 MW cm−2). Deeper structural and theoretical analysis suggests that the ordered arrangement of NLO-active motifs, [Ge2OS6] dimers and [FeS4] tetrahedra, makes significant contributions to the strong deff and large birefringence (Δn). This work not only demonstrates a PM Fe-based NCS material for the first time but also puts forward a new design avenue for high-performance IR-NLO materials.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2023
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IF 9.9
Ye Zichen,Li Yun,Li Jingchao,Hu Xinyan,Zheng Jinyang,Zhang Gongxin,Xiang Sijin,Zhu Tianbao,Guo Zhide,Chen Xiaolan
Lactic acid (LA) plays a major role in the occurrence, development, and spread of cancer. Enlightened by its high accumulation in tumor site, a novel lactate oxidase (LOD) conjugated two-dimensional Pd@Ir nanoplatform (Pd@Ir-LOD, PIL) was fabricated to combine cascade reaction with photothermal for tumor therapy. In detail, the overexpressed LA in tumor microenvironment (TME) was a key factor to activate the PIL-based cascade reaction: (1) Plenty of H 2 O 2 could be generated from LA by the catalysis of LOD with O 2 ; (2) potent OH was produced from H 2 O 2 due to the peroxidase (POD)-like activity of PIL; (3) meantime, PIL’s catalase (CAT)-like activity could decompose part H 2 O 2 into O 2 to achieve the purpose of LA cyclic oxidization. Moreover, the reduced glutathione (GSH) scavenging capability of PIL might protect the produced reactive oxygen species (ROS) from being cleared to further improve the cascade therapeutic effect. More importantly, PIL had excellent photothermal conversion efficiency (37.35%) and manifested a surprising temperature rising effect in tumor. Taken together, the decreasing LA concentration, accumulation of high-toxic ROS, the depletion of GSH together with the higher intra-tumoral temperature potently enhanced in vivo antitumor therapy. Therefore, a promising therapeutic tactic based on PIL integrating endogenous LA consumption, chemodynamic therapy (CDT), and photothermal therapy (PTT) has been put forward.
研究领域:
癌症治疗
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纳米医学
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生物化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-11
·
IF 16.6
Pillai Hemanth Somarajan,Li Yi,Wang Shih-Han,Omidvar Noushin,Mu Qingmin,Achenie Luke E. K.,Abild-Pedersen Frank,Yang Juan,Wu Gang,Xin Hongliang
The electrochemical ammonia oxidation to dinitrogen as a means for energy and environmental applications is a key technology toward the realization of a sustainable nitrogen cycle. The state-of-the-art metal catalysts including Pt and its bimetallics with Ir show promising activity, albeit suffering from high overpotentials for appreciable current densities and the soaring price of precious metals. Herein, the immense design space of ternary Pt alloy nanostructures is explored by graph neural networks trained on ab initio data for concurrently predicting site reactivity, surface stability, and catalyst synthesizability descriptors. Among a few Ir-free candidates that emerge from the active learning workflow, Pt 3 Ru-M (M: Fe, Co, or Ni) alloys were successfully synthesized and experimentally verified to be more active toward ammonia oxidation than Pt, Pt 3 Ir, and Pt 3 Ru. More importantly, feature attribution analyses using the machine-learned representation of site motifs provide fundamental insights into chemical bonding at metal surfaces and shed light on design strategies for high-performance catalytic systems beyond the d -band center metric of binding sites.
研究领域:
电化学
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催化
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机器学习
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
iScience
·
2021
·
IF 5.458
Linghui Peng,Jianyu Huang,Ruiping Zou,Bin Su
Controllable IR-reflection systems can be applied to displays, adaptive military camouflages, thermal managements, and many other fields. However, current reported controllable IR-reflection systems suffer from utilizing rigid materials, complicated devices, or high working temperature/voltage, which are not suitable for their widespread applications toward soft systems. Herein, inspired by cephalopods, we demonstrate a facile and scalable method for adaptive IR reflection based on a Janus rubber film, which is composed of aluminum-coated microsheets (AMSs)/rubber composite top and a rubber only bottom. Expansion of the Janus rubber film causes random arrangement of AMSs to stay planar, resulting in the change from IR scattering to concentrated IR reflection. By fixing the Janus rubber films upon the arranged tubes, as-prepared arrays could display complex and changeable patterns by selectively pumping tubes. Being facile and of general validity, our strategies broaden the scope of future controllable IR reflecting applications for environmental IR camouflages and displays.
研究领域:
材料科学
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仿生学
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光学工程
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
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IF 3.671
Jun Yuan,Shuxian Chen,Liping Wang,Tingting Xu,Xu Shi,Yi Jing,Haijiang Zhang,Yange Huang,Ying Xu,Dong Li,Xing Chen,Jianhui Chen,Qingping Xiong
The aim of this paper was to prepare purified fractions of polysaccharides from Monetaria moneta Linnaeus and further compare their characteristics and antioxidant activities. Firstly, three novel purified fractions, named MM-P1, MM-P2 and MM-P3, were successfully prepared by a DEAE-Sepharose fast-flow column. Then, their characteristics were compared using chemical testing, FT-IR, GC and HPGPC. The results suggested that MM-P3 had higher molecular weights than MM-P1 and MM-P2. MM-P1 was consisted of glucose, MM-P2 was consisted of glucose and xylose, and MM-P3 was comprised of glucose, xylose and mannose. Differed from MM-P1 and MM-P2, MM-P3 had sulfuric radical and uronic acid groups. Finally, their antioxidant activities were also compared. We found that MM-P3 exhibited better antioxidant bioactivities than MM-P1 and MM-P2. The data demonstrated that three purified fractions derived from different adsorption capacity of DEAE-Sepharose fast-flow column possessed different structural characteristics and antioxidant activity.
研究领域:
生物化学
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药理学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
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IF 5.636
Chunxiang Li,Hongyang Wang,Jing Shen,Bo Tang
Photoactive material is the most crucial factor which intimately determines analytical performances of the photoelectrochemical sensor. On the basis of the high affinity of dipyrido [3,2-a:2′,3′-c] phenazine (dppz) with DNA helix, a novel photoactive intercalator, [(ppy)2Ir(dppz)]+PF6–(ppy = 2-phenylpyridine and dppz = dipyrido [3,2-a:2′,3′-c] phenazine) was prepared and characterized by UV–vis absorption spectroscopy, fluorescence spectroscopy, and cyclic voltammetry. The photoelectrochemical properties of the as-prepared iridium(III) complex immobilized on the ITO electrode was investigated. Either cathodic or anodic photocurrent generation can be observed when triethanolamine (TEOA) or dissolved O2 is used as a sacrificial electron donor/acceptor, respectively. The probable photocurrent-generation mechanisms are speculated. A highly sensitive iridium(III) complex-based photoelectrochemical sensor was proposed for DNA detection via hybridization chain reaction (HCR) signal amplification. Under optimal conditions, the biosensor was found to be linearly proportional to the logarithm of target DNA concentration in the range from 0.025 to 100 pmol L–1 with a detection limit of 9.0 fmol L–1 (3σ). Moreover, the proposed sensor displayed high selectivity and good reproducibility, demonstrating efficient and stable photoelectric conversion ability of the Ir(III) complex.
研究领域:
生物化学
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分析化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemCatChem
·
2022
·Vol. 15
·期 4
·e202201405
·
IF 5.497
Lei Zeng,Wei Li,Xueer Wei,Jiawei Cheng,Wei Zhou,Yanping Zheng,Fan Cai,Yuefeng Liu,Kang Cheng,Qinghong Zhang,Ye Wang
Graphical IrGa/Al 2 O 3 catalyst with atomical metal dispersion exhibits excellent non-oxidative propane dehydrogenation performance with a propylene selectivity of 98 % at an 18 % propane conversion for 100 hours, comparable to that of classical Pt-based catalysts. An enhanced synergetic effect between metallic Ir and partially reduced GaO x oxide was found. Industrial catalysts for alkane dehydrogenation to olefins suffer from fast deactivation due to the coking and sintering of active metal under harsh reaction conditions. Herein, iridium, a noble metal rarely applied in C−H activation, has been employed to construct an ultra-stable IrGa/Al 2 O 3 catalyst with atomical metal dispersion for non-oxidative propane dehydrogenation (PDH). A synergetic effect between metallic Ir and GaO x is discovered which contributes to both high PDH activity and propylene selectivity. Notably, the Ir 0.5 Ga 2 /Al 2 O 3 with 0.5 wt % of Ir and 2.0 wt % of Ga exhibited a propylene selectivity of 98 % at a 19 % propane conversion at 550 °C and 86 % at a 35 % propane conversion at 600 °C. A stable PDH performance of 100 h was observed after a deactivation process at the initial reaction stage. The catalytic performance of the IrGa/Al 2 O 3 is comparable to that of Pt-based catalysts, endowing the Ir-based catalyst with great potential in dehydrogenation reactions.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 5
·056523
·
IF 4.386
Chuanhui Zhu,Guo-Hong Cai,Chongyang Yuan,Bin Huang,Guangqin Li,Mark Croft,Martha Greenblatt,Man-Rong Li
Exploring a simple model system to realize the intrinsic guidelines of activity for oxide electrocatalysts is urgent and important. Here, we introduce delafossite oxides A2IrO3 (A = Li, Na, Cu) as a family of oxygen evolution reaction electrocatalysts in alkaline media. We show that, in Cu2IrO3, the intrinsic intersite charge transfer between Cu and Ir improves the electrocatalytic activity by simultaneously increasing the conductivity and reducing the Tafel slope down to 51 mV dec−1 with an overpotential η10 = 361 mV. Through a comparative study, the improved activity of Cu2IrO3 is attributed to the increase of Ir 5d projected electronic density of states with extended Ir–O bond length. This study provides insights into advanced catalyst design through tailoring the active site of oxides by the modulation of electronic states in a given structural motif.
研究领域:
材料科学
·
电化学
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催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）