Molecular Catalysis
·
2024
·
IF 3.9
Qinglei Wu,Chenyang Shen,Chang-jun Liu
Molybdenum carbide is a promising support to tune the metal reactivity, which originates from the interaction between metal and support. In this work, Pd/β-Mo 2 C was prepared using a deposition-precipitation method for selective hydrogenation of acetylene. The high temperature calcination is employed to modulate the interaction between Pd and β-Mo 2 C. The Pd/β-Mo 2 C catalyst calcined at 600 °C exhibits significant promotion in selective hydrogenation, which shows 100 % acetylene conversion and 81.4 % ethylene selectivity at 160 °C. The activity promotion originates from the enhanced electronic metal-support interaction, which induces a shift of Pd 3d to higher binding energy. Besides, the Pd species become atomically dispersed after calcination. The changes in geometric and electronic structure suppress the formation of Pd hydrides, which consequently inhibits the excessive hydrogenation capacity of Pd. The structure variation also affects the adsorption of ethylene. No strong adsorbed ethylene (di-σ bonded ethylene) can be identified, which is conducive to the improvement of ethylene selectivity. Density functional theoretical (DFT) calculations confirm that Pd on β-Mo 2 C is positively charged. The desorption energy of C 2 H 4 * (0.78 eV) is significantly lower than that of further hydrogenation (1.45 eV), which explains the improved ethylene selectivity of the calcinated catalyst. The present study indicates calcination is an effective method to tune the activity of Pd/β-Mo 2 C for reactions beyond selective hydrogenation of acetylene.
研究领域:
催化
·
化学工程
·
材料科学
·
理论化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 21
·10591-10598
·
IF 8.867
Xinzheng Yue,Shasha Yi,Runwei Wang,Zongtao Zhang,Shilun Qiu
In the development of photocatalytic hydrogen (H2) production, designing and optimizing photocatalyst nanostructures with efficient charge transfer and separation for catalytically active sites are still a great challenge. Herein, a well-controlled synthetic strategy is developed to prepare an Mo2C/TiO2 hetero-nanostructure, in which the TiO2 3D hierarchical configuration is loaded with highly dispersed Mo2C nanoparticles. This heterostructure achieves the excellent photocatalytic activity of 39.4 mmol h−1 g−1 with its rate ∼25 times higher than that of pristine TiO2. Also, our photocatalysts process excellent long-term durability (>20 h). The impressive photocatalytic H2 activity of Mo2C/TiO2 indicates favourable charge carrier dynamics, as determined by the results of photoluminescence (PL), time-resolved photoluminescence (TRPL), surface photovoltage (SPV), and open circuit potential (OCP) decay curves. Moreover, this study provides a guide for researchers to design new functional materials with excellent hydrogen production activity.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Lizhen Zeng,Xiaofen Chen,Hongying Li,Juan Xiong,Meihua Hu,Xin Li,Weishan Li
A novel composite, polydopamine-modified Mo 2 C/MoO 2 nanoparticles (HD-Mo 2 C/MoO 2 ), as anode electrocatalyst for microbial fuel cells (MFCs), is synthesized via carbon thermal reduction and following in situ polydopamine modification. The physical and electrochemical characterizations show that Mo 2 C/MoO 2 nanoparticles can be well dispersed through polydopamine modification and the resulting HD-Mo 2 C/MoO 2 exhibits excellent electrocatalytic activity compared with unmodified Mo 2 C/MoO 2 . The MFC using HD-Mo 2 C/MoO 2 as anode electrocatalyst achieves a maximum output power density of 1.64 ± 0.09 W m −2 , which is 39% higher than that using Mo 2 C/MoO 2 (1.18 ± 0.08 W m −2 ) as anode electrocatalyst. This excellent performance is attributed to modification of PDA, HD-Mo 2 C/MoO 2 shows better hydrophilicity and electrocatalytic activity toward the direct oxidation of bacterial metabolites than unmodified Mo 2 C/MoO 2 .
研究领域:
生物化学
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材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Rui Jiang,Liu Pi,Bowen Deng,Liangyou Hu,Xianglin Liu,Jiaxin Cui,Xuhui Mao,Dihua Wang
A binderless composite cathode for efficient electrocatalytic hydrogen evolution reaction (HER), Mo2C-decorated carbon cloth (denoted as CC/MC), is simply fabricated via a novel and unique strategy which involves a solid–solid phase interfacial electrochemical reaction between carbon fiber and bulk-MoS2 in molten NaCl–KCl (700 °C). MoS2, evenly coated on carbon cloth (CC), is electrochemically reduced in situ and readily reacts with the carbon fibers of CC current collector to form a Mo2C nanoparticle layer. The experiment and calculation results show that the applied electric field results in a declining migration barrier of Mo vacancies in Mo2C lattice, which promotes the diffusion of Mo atoms into carbon across the interfacial Mo2C layer, thereby impelling the combination of Mo with C in depth. The electrochemical tests indicate that the optimized cathode (CC/MC-2) exhibits a small overpotential of 134.4 mV at 10 mA cm–2 and stays stable for HER in acidic media. The catalytic capacity for N2 reduction of CC/MC-2 is analyzed. In addition, a Ni-doped Mo2C-modified carbon fabric electrode with enhanced HER activity (η10 = 96.6 mV) can be prepared through a similar process.
研究领域:
材料科学
·
电化学
·
能源转换与储存
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Energy
·
2018
·
IF 13.12
Xinzheng Yue,Shasha Yi,Runwei Wang,Zongtao Zhang,Shilun Qiu
In artificial photocatalysis for hydrogen (H 2 ) generation from water reduction, low apparent quantum efficiency (AQE) always confines the photocatalytic conversion efficiency. Here, we demonstrate a new strategy for the design and synthesis of one-dimensional (1D) SrTiO 3 @Mo 2 C core-shell nanostructure for highly enhanced photocatalytic H 2 generation activity. The thin nanolayer of Mo 2 C improves the interfacial conductivity, facilitates transport of photo-generated charge carriers as well as prolongs charge carriers’ lifetime, that minimizing the recombination of photo-generated electrons and holes. Thus SrTiO 3 @Mo 2 C hybrid achieves drastically enhanced photocatalytic H 2 generation rate up to 7.93 mmol h −1 g −1 with respect to the pristine SrTiO 3 (0.53 mmol h −1 g −1 ) in a solar-driven reaction system, with an AQE of 29.3% at 313 nm. The charge carrier dynamics based mechanism was further confirmed by analysis of time-resolved photoluminescence (TRPL), surface photovoltage (SPV), transient photovoltage (TPV), open circuit potential (OCP) decay curves as well as the electrochemical impedance spectroscopy (EIS) measurements. It is unambiguously to demonstrate that Mo 2 C is a highly active cocatalyst to dramatically boost the charge separation for photocatalytic water reduction.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Advances
·
2020
·Vol. 2
·期 8
·3334-3340
·
IF 0
Jieyu Xu,Lin Ge,Yajun Zhou,Guangyu Jiang,Liang Li,Yunheng Li,Yongsheng Li
Heteroatom doping has been proved to be an effective strategy to optimize the activity of hydrogen evolution reaction (HER) catalysts. Herein, we report N, P, S multi-doped Mo2C/C composites exhibiting highly efficient HER performance in acidic solution, which are facilely fabricated via annealing of N, P, S-containing MoOx–polyaniline (MoOx–PANI) hybrid precursors. The optimized N, P, S multi-doped Mo2C/C catalyst with a moderate P dopant level (NPS-Mo2C/C-0.5) exhibits excellent performance with an overpotential of 53 mV to achieve a current density of 20 mA cm−2, a Tafel slope of 72 mV dec−1 and good stability in acidic electrolytes. Based on the study of XPS, EPR and 31P MAS NMR, the excellent electrocatalytic performance could be attributed to the effective electronic configuration modulation of both Mo2C nanorods and the carbon matrix, derived from stronger synergistic N, P, S multi-doping coupling effects. This work provides a promising methodology for the design and fabrication of multi-doped transition metal based electrocatalysts via electronic structure engineering.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
Nanomaterials
·
2024
·Vol. 14
·期 3
·243
·
IF 4.4
Zhaofeng Zhai,Chuyan Zhang,Bin Chen,Lusheng Liu,Haozhe Song,Bing Yang,Ziwen Zheng,Junyao Li,Xin Jiang,Nan Huang
Developing non-precious metal-based electrocatalysts operating in high-current densities is highly demanded for the industry-level electrochemical hydrogen evolution reaction (HER). Here, we report the facile preparation of binder-free Mo2C-Mo2N heterostructures on carbon nanowalls/diamond (CNWs/D) via ultrasonic soaking followed by an annealing treatment. The experimental investigations and density functional theory calculations reveal the downshift of the d-band center caused by the heterojunction between Mo2C/Mo2N triggering highly active interfacial sites with a nearly zero ∆GH*value. Furthermore, the 3D-networked CNWs/D, as the current collector, features high electrical conductivity and large surface area, greatly boosting the electron transfer rate of HER occurring on the interfacial sites of Mo2C-Mo2N. Consequently, the self-supporting Mo2C-Mo2N@CNWs/D exhibits significantly low overpotentials of 137.8 and 194.4 mV at high current densities of 500 and 1000 mA/cm2, respectively, in an alkaline solution, which far surpass the benchmark Pt/C (228.5 and 359.3 mV) and are superior to most transition-metal-based materials. This work presents a cost-effective and high-efficiency non-precious metal-based electrocatalyst candidate for the electrochemical hydrogen production industry.Keywords:hydrogen evolution reaction;high current density;carbon nanowalls;diamond;Mo2C;Mo2N;heterostructure
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 2
·192
·
IF 4
Dongshi Feng,Jiangdong Dai,Yongsheng Yan,Chunxiang Li
Developing a catalyst with excellent electrical conductivity and catalytic performance for on-site testing of residual imidacloprid is significant and challenging. In situ growth of Mo2C nanodots on Co-induced N-doped carbon nanotubes (Co/Mo2C/N-CNT) was synthesized to construct a molecularly imprinted electrochemical sensor for the detection of imidacloprid. The results proved that the catalytic performance of Co/Mo2C/N-CNT for imidacloprid was over two times higher than those of Co/N-CNT and commercial CNT. This improvement was attributed to the formation of a heterostructure between Co species, Mo2C, and N-CNT, which facilitated highly exposed catalytic active sites. Additionally, the abundant Mo2C nano-dots promoted interfacial charge transfer to achieve optimal dynamics. The optimum preparation parameters of the catalysts were obtained by response surface methodology. By analyzing the relationship between different pH values and peak potential, as well as the influence of different scanning rates on peak potential, it was deduced that the possible electrocatalytic mechanism of imidacloprid involved the reduction of the nitro group to a hydroxylamine group and H2O. Under optimal conditions, the limit of detection (LOD) was 0.033 × 10−6mol·L−1(R2= 0.99698), and the linear range was 0.1 × 10−6~100 × 10−6mol·L−1. The application effect of the prepared sensor was evaluated by measuring the imidacloprid in two kinds of tea, indicating that the sensor possessed good sensitivity and selectivity, and was capable of meeting the requirements of on-site detection.
研究领域:
分析化学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Qihuan Lv,Yu Zhou,Linlin Wang,SanE Zhu,Hongdian Lu,Wenjie Yang,Chunxiang Wei
The advancement of novel MXene materials characterized by heightened stability and remarkable antibacterial attributes has garnered substantial attention in recent research endeavours. In this article, it is first time to prepare boron dipyrromethene (BODIPY) modified Mo 2 C nanosheets (BODIPY-Mo 2 C) via electrostatic interactions to achieve the desirable antibacterial property, enriching by both photothermal and photodynamic effects. The photothermal conversion efficiency of the produced Mo 2 C nanosheets reached to 42.6 %. Furthermore, in the photothermal antibacterial tests against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), both Mo 2 C and BODIPY-Mo 2 C demonstrated 100 % antibacterial efficiency at a concentration of 100 μg·mL −1 . Remarkably, at a lower concentration gradient of 75 μg·mL −1 , BODIPY-Mo 2 C nanosheets showed clearly enhanced antibacterial capabilities compared to pure Mo 2 C, underscoring the efficacy of BODIPY in boosting the antibacterial performance of Mo 2 C.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
·
抗菌研究
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Yijin Shu,Sina He,Lifang Xie,Hang Cheong Chan,Xiang Yu,Lichun Yang,Qingsheng Gao
The hydrogenation of nitroarenes to value-added aromatic amines requires active and selective catalysts. Due to the good efficiency, economic cost and high earth-abundance, Ni-based nanostructures emerge as the promising catalysts, which are however limited by the poor dispersion and unsatisfied durability. Herein, Mo 2 C nanowires was introduced as a versatile support towards the highly dispersive Ni owing to the strong metal-support interactions on carbide surface, accomplishing the high activity in the hydrogenation of 3-nitrobenzoic acid, 4-nitrobenzoic acid and nitrobenzene. However, the presence of water that promoted the selective hydrogenation unfortunately deactivated Ni species. An effective carbon coating was further introduced to remarkably enhance the stability, protecting active Ni from corrosive H + and H 2 O. This work elucidates a feasible way towards efficient and stable catalysts by the introduction of both carbide supports and carbon coating, shedding some light on the development of high-performance catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Xiaohui Ma,Chaojun Ren,Hongda Li,Xintong Liu,Xinyang Li,Kun Han,Wenjun Li,Yifei Zhan,Ajmal Khan,Zhidong Chang,Changyan Sun,Hualei Zhou
Currently, designing novel noble-metal-free photocatalysts with efficient carriers migration and catalytically active sites have been a researching hotspot in photocatalytic hydrogen evolution. In this paper, a novel noble-metal-free Mo 2 C-In 2 S 3 heterojunction was synthesized by a simple hydrothermal method. Morphology characterization revealed In 2 S 3 was attached to Mo 2 C. Electrochemical results showed Mo 2 C improved the interface conductivity, and promoted the transportation of photogenerated carriers. Under visible light, the optimal Mo 2 C-In 2 S 3 composite achieved a H 2 generation rate of 535.58 μmol h −1 g −1 , which was 175.6 and 25.8 times higher than pristine In 2 S 3 (3.05 μmol h −1 g −1 ) and In 2 S 3 -1% Pt (20.73 μmol h −1 g −1 ). In addition, a reasonable mechanism of the elevated photocatalytic activity was also discussed. This study demonstrates commercial Mo 2 C has an important effect of separating carriers and replacing Pt as co-catalyst in heterojunctions. This research also provides a method to design and synthesize new noble-metal-free photocatalysts for excellent hydrogen production activity.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Junmei Liang,Ranran Ding,Yulong Wu,Yu Chen,Kejing Wu,Yongqiang Meng,Mingde Yang,Yaowu Wang
Hydrotreatment of heteroatomic model compounds in microalgae-based bio-oils into diesel-like hydrocarbons was carried out over carbon nanotubes (CNTs)-supported β-Mo 2 C catalyst with superior activity and selectivity under a mild condition (≤200 °C). The results show that stearic acid and hexadecanamide can be completely converted into n -C 15 –C 18 alkanes over β-Mo 2 C/CNTs catalyst. The β-Mo 2 C/CNTs favors the pathway of hydrogenation–dehydration–hydrogenation to produce n -octadecane with an optimal yield of 91.24% at a lower temperature of 180 °C during hydrotreating process of stearic acid. The recycle tests demonstrate that the β-Mo 2 C/CNTs exhibits excellent stability, and can be reused for seven times consecutively without reduction of catalytic stability. Based on the determined products, a brief reaction pathway is proposed. Therefore, a novel approach to produce diesel-like hydrocarbons via catalytic hydrotreatment of microalgae-based bio-oils over β-Mo 2 C/CNTs is introduced, which provides a basic research as well as technical parameters for its further industrialization.
研究领域:
能源生物学
·
催化化学
✓ 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）