VACUUM
·
2024
·
IF 3.8
Jing Xu,Lu Qiao,Yadong Yang,Yong Liu,Yuanyuan Zhu,Jinbing Cheng,Hongjun Wang,Rui Xiong
Resistive random-access memory ( RRAM) has been widely studied because of its high information storage density and easy integration, and it has potential to replace traditional memory storage means. However, it is prone to random formations and fracture of conductive filaments , which limits its commercial applications. In this study, magnetron sputtering was used to deposit NbO x films on different substrates modified with different concentrations of Au-nanoparticles (NPs). The as developed Pt-Au min /NbO x /W tip device with the lowest concentration of Au-NPs modified bottom electrode exhibited the best performance; the V set distribution of the device was more concentrated, V reset decreased significantly, the distribution range was narrow, and the resistance distribution of high and low resistance states (HRS and LRS, respectively) was more stable. Modification of the bottom electrode with Au-NPs did not change the ohmic conduction behavior of NbO x RRAM in LRS; however, it changed the resistance switching mechanism from SCLC to P–F effect modified SCLC . The Au-NPs modified bottom electrode acted like a tip, enhancing the local electric field and promoting the formation of conductive filaments near the NPs. This work explains the internal mechanism for improving RRAM properties using a local electric field and provides theoretical guidance for enabling the rapid commercialization of RRAM.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Lin Dong,Jie Xia,Yong Guo,Xiaohui Liu,Haifeng Wang,Yanqin Wang
Efficient and selective cleavage of C aromatic -C linkages in lignin to enhance the productivity of monocyclic aromatic hydrocarbons is an extremely challenging and attractive task. Previously, we reported a Ru/NbOPO 4 catalyst that realized the catalytic cleavage of both interunit C-C and C-O bonds in one-pot lignin conversions [ Chem , 2019, 5, 1521–1536]. However, the roles of NbO x species in the selective C aromatic -C cleavage are not clear and need to be extensively studied. Herein, we focus on the exploration of the catalytic mechanisms of C aromatic -C bond cleavage over NbO x -supported Ru catalyst, by comparing with those of Ru/TiO 2 , Ru/ZrO 2 , and Ru/Al 2 O 3 catalysts. It shows that the Ru/Nb 2 O 5 catalyst exhibits high activity and remarkable selectivity to monocyclic hydrocarbons. A combined diffuse reflectance infrared Fourier Transform spectra (DRIFTS) and density functional theory (DFT) calculation analysis unambiguously confirmed that (i) NbO x not only can strongly adsorb phenylcyclohexane via benzene ring, but also selectively activate C aromatic -C bond between benzene ring and cyclohexane ; (ii) NbO x can promote the protonation of phenylcyclohexane with the assistance of H 3 PO 4 ; and (iii) NbO x can significantly reduce the barrier of C aromatic -C bonds cleavage of the carbocation intermediate (C 6 H 5 (H)C 6 H 11 + ). A detail underlying mechanism has been established, which would have further implications to promote the design of new, high efficient catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 46
·24598-24607
·
IF 11.301
Chizhong Wang,Rong Wang,Yue Peng,Jianjun Chen,Zhen Chen,Haibo Yin,Junhua Li
Development of new groups of oxygen evolution reaction (OER) electrocatalysts based on transitional metal materials is highly attractive for renewable energy conversion and storage. Here we report a new FeNb (oxy)hydroxide catalyst, which delivered a high OER activity with an overpotential as low as 0.34 V (at 10 mA cm−2). To attain a homogeneous mixing of metal components, niobium was initially incorporated into the framework of iron oxalate dihydrate. The mixed oxalate could be structurally transformed into short-range ordered (oxy)hydroxide, the reactive species for the OER. Incorporation of Nb has been demonstrated to improve the intrinsic OER activity based on Fe species and to accelerate the charge-transfer kinetics across the solid-electrolyte interface. It is also found that strong Fe–Nb interaction can induce the formation of high-valent Fe species. Theoretical calculation results further illustrate the role of NbOx in the OER mechanism, in which Fe serves as the active site and the Nb species can promote the conversion of *OH to *O intermediates to reduce the OER overpotential.
研究领域:
材料科学
·
电化学
·
可再生能源
✓ 已验证
DOI
高影响因子
Energy Technology
·
2025
·Vol. 13
·期 9
·2402044
·
IF 3.6
Dan Lu,Guang Zhu,Wei Liu,Kaixin Wang,Qixuan Wang,Chenxi Xu
The Pt/C catalysts applied in proton exchange membrane fuel cell (PEMFC) suffer CO poisoning in the anode, which notably deteriorates the device performance. The metal–support interaction that decreases the CO oxidation stripping potential is a suitable way to prevent CO anchoring the active sites that can reduce or even avoid the poisoning. Herein, the Pt is supported by amorphous NbO x ( x = 1.0–2.5) and CNT to form Pt@NbO x + CNT catalyst, which not only displays the lower initial and peak CO oxidation stripping potential but also exhibits the striking anti-CO poisoning and hydrogen oxidation reaction properties. The initial and peak potential for oxidation stripping of Pt@NbO x + CNT catalyst are 0.162 and 0.332 V, respectively. Moreover, the PEMFC based on Pt@NbO x + CNT catalyst in 100 ppm CO/H 2 exhibits a peak power density of 1.98 W cm −2 , only 17% reduction compared to that in pure hydrogen and the catalyst remains 10 h stability at 0.4 V.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2015
·
IF 2.002
Lei Chen,Zhichun Si,Xiaodong Wu,Duan Weng,Zhenwei Wu
A MnO x –NbO x –CeO 2 catalyst for low temperature selective catalytic reduction (SCR) of NO x with NH 3 was prepared by a sol–gel method, and characterized by NH 3 –NO/NO 2 SCR catalytic activity , NO/NH 3 oxidation activity, NO x /NH 3 TPD , XRD , BET, H 2 -TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The results indicate that the MnO x –NbO x –CeO 2 catalyst shows excellent low temperature NH 3 -SCR activity in the temperature range of 150–300°C. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NO x adsorption. As the NO 2 content increases in the feed, water vapor does not affect the activity in NO 2 SCR. Meanwhile, water vapor significantly enhances the N 2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH 4 NO 3 into N 2 O.
研究领域:
环境催化
·
大气污染控制
·
材料化学
·
表面科学
·
化学工程
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 19
·10168-10176
·
IF 9.3
Weixiang Guan,Chen Cao,Fei Liu,Aiqin Wang,Tao Zhang
Chemocatalytic conversion of cellulose to ethanol provides an alternative route for biofuel production with a theoretical carbon yield of 100%; however, it faces significant challenges of high catalyst cost and poor catalyst stability. In this work, we report a new strategy to decrease the use of expensive noble metals, by decorating mononuclear NbOx on a low-Pt Pt/WOx catalyst surface. The resulting 0.1Nb/0.5Pt/WOx catalyst gave rise to an ethanol yield of 33.7% together with an ethylene glycol yield of 21.8%, and the noble metal efficiency reached 25.90 gethanol gPt−1 h−1, an increase by a factor of 2–10 compared to those in the literature. Moreover, the catalyst stability was significantly enhanced by the decoration of mononuclear NbOx, allowing for recycling at least 7 times without obvious activity decay. Characterization revealed that Pt was highly dispersed at subnanometer and single atom scales, and modification with mononuclear NbOx facilitated hydrogen spillover and created more oxygen vacancies on the WOx surface upon hydrogen reduction, thus generating a higher density of Brønsted acid sites. This effect not only favored cellulose conversion to ethylene glycol but also promoted the hydrogenolysis of ethylene glycol to ethanol.
研究领域:
化学催化
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2025
·
IF 4.9
Yubin Yuan,Shujing Zhao,Qiang Wu,Zifan Li,Chuanyu Han,Xin Li,Long Hu,Mingchao Yang,Weihua Liu,Li Geng
Biological perception systems are renowned for their ability to process environmental stimuli with remarkable energy efficiency, primarily through spike-based communication and event-driven mechanisms. Inspired by these, in this paper, we propose an infrared artificial neuromorphic perception neuron (IR-ANPN) designed to detect infrared (IR) light, enabling sensory perception beyond the visible spectrum. The IR-ANPN is designed based on a one-transistor-one-memristor (1T1M) architecture, which consists of a PbS quantum dots-decorated Indium Gallium Zinc Oxide (IGZO) thin film transistor (PbS-QDs/IGZO TFT) and an NbO x Mott memristor. The PbS-QDs/IGZO TFT is responsible for detecting infrared light stimuli, while the NbO x Mott memristor converts these stimuli into neuromorphic spikes. The IR-ANPN can operate in an event-driven mode, which means it transmits spikes only when exposed to IR light, ensuring energy efficiency by remaining dormant in the absence of relevant stimuli. The paper also showcases the potential of the IR-ANPN by constructing a neuromorphic infrared detection array. Combined with a spiking neural network (SNN), the system achieves 92 % recognition accuracy on the MNIST dataset by encoding pixel intensity as spiking frequency. The IR-ANPN architecture enhances sensory capabilities through a neuromorphic approach, enabling the detection of non-visible wavelengths with remarkable energy efficiency and laying the foundation for future intelligent sensing technologies.
研究领域:
神经形态工程
·
红外传感
·
忆阻器器件
·
光电子学
·
人工智能硬件
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-13
·
IF 14.7
Zhang Bin,Yuan Haiyang,Liu Ye,Deng Zijie,Douthwaite Mark,Dummer Nicholas F.,Lewis Richard J.,Liu Xingwu,Luan Sen,Dong Minghua,Wang Tianjiao,Xu Qingling,Zhao Zhijuan,Liu Huizhen,Han Buxing,Hutchings Graham J.
Alkoxycarbonylation reactions are common in the chemical industry, yet process sustainability is limited by the inefficient utilization of CO. In this study, we address this issue and demonstrate that significant improvements can be achieved by adopting a heterogeneously catalyzed process, using a Ru/NbO x catalyst. The Ru/NbO x catalyst enables the direct synthesis of methyl propionate, a key industrial commodity, with over 98% selectivity from CO, ethylene and methanol, without any ligands or acid/base promoters. Under ambient CO pressure, a high CO utilization efficiency (336 mmol ester mol CO −1 h −1 ) is achieved. Mechanistic investigations reveal that CO undergoes a methoxycarbonyl (COOCH 3 ) intermediate pathway, attacking the terminal carbon atom of alkene and yielding linear esters. The origins of prevailing linear regioselectivity in esters are revealed. The infrared spectroscopic feature of the key COOCH 3 species is observed at 1750 cm −1 (C=O vibration) both experimentally and computationally. The broad substrate applicability of Ru/NbO x catalyst for ester production is demonstrated. This process offers a sustainable and efficient approach with high CO utilization and atom economy for the synthesis of esters.
研究领域:
化学工程
·
可持续化学
·
催化
·
有机合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Zhibin Li,Haonan Zhong,Xiongjun Liu,Fu-Kuo Chiang,Rui Li,Houwen Chen,Xianzhen Wang,Chubin Wan,Yuan Wu,Hui Wang,Suihe Jiang,Xiaobin Zhang,Zhaoping Lu
Proton exchange membrane water electrolysis (PEMWE) holds substantial promise for effectively utilizing renewable energy to produce green hydrogen. However, it faces critical durability challenges due to acid-driven catalyst degradation under intermittent renewable power. Here, this study reports a dynamic dissolution-deposition equilibrium that achieves exceptional hydrogen evolution reaction (HER) stability through rational design of a high-entropy alloy-derived architecture. Dealloying FeCoNiNbPt HEA creates a porous scaffold with dual-functional components: an amorphous NbOx buffer suppressing metal dissolution, while multicomponent Pt 3 (FeCoNi) nanocrystals synergistically enhancing HER activity (137 mV@1 A cm −2 , 2.5 × lower than Pt/C) that thermodynamically favors redeposition. This dynamic self-adaptive mechanism maintains equilibrium under harsh operating conditions, demonstrating exceptional durability (>2200 h @1 A cm −2 and 1 000 000 cycles). The self-supported catalysts can be easily mass-produced with 8.87 wt.% Pt loading (60% reduction vs Pt/C), indicating its industrial applicability. The equilibrium-driven design paradigm opens new avenues for industrial proton-exchange-membrane devices operating under fluctuating power.
研究领域:
能源材料
·
电化学
·
催化
·
纳米技术
·
合金工程
·
可再生能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）