Journal of the American Chemical Society
·
2024
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IF 14.4
Yanliang Zhou,Lili Liang,Congying Wang,Fuxiang Sun,Lirong Zheng,Haifeng Qi,Bin Wang,Xiuyun Wang,Chak-tong Au,Junjie Wang,Lilong Jiang,Hideo Hosono
To date, NH3 synthesis under mild conditions is largely confined to precious Ru catalysts, while nonprecious metal (NPM) catalysts are confronted with the challenge of low catalytic activity due to the inverse relationship between the N2 dissociation barrier and NHx (x = 1–3) desorption energy. Herein, we demonstrate NPM (Co, Ni, and Re)-mediated Mo2CTx MXene (where Tx denotes the OH group) to achieve efficient NH3 synthesis under mild conditions. In particular, the NH3 synthesis rate over Re/Mo2CTx and Ni/Mo2CTx can reach 22.4 and 21.5 mmol g–1 h–1 at 400 °C and 1 MPa, respectively, higher than that of NPM-based catalysts and Cs–Ru/MgO ever reported. Experimental and theoretical studies reveal that Mo4+ over Mo2CTx has a strong ability for N2 activation; thus, the rate-determining step is shifted from conventional N2 dissociation to NH2* formation. NPM is mainly responsible for H2 activation, and the high reactivity of spillover hydrogen and electron transfer from NPM to the N-rich Mo2CTx surface can efficiently facilitate nitrogen hydrogenation and the subsequent desorption of NH3. With the synergistic effect of the dual active sites bridged by H-spillover, the NPM-mediated Mo2CTx catalysts circumvent the major obstacle, making NH3 synthesis under mild conditions efficient.
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Qinsheng Wang,Yiyi Fan,Chengliang Wu,Yun Jin,Claudia Li,Jaka Sunarso,Xiuxia Meng,Naitao Yang
Research on gas separation membrane has targeted upon maximizing the selectivity and permeance. The development of 2D materials ( e.g. , MXene) gives a novel avenue to surpass the “trade-off” among the membrane selectivity and permeability. However, randomly stacked nanosheets and the regulation of interlayer spacing for MXene nanosheets hinder the development of MXene membrane. To this end, we designed a Pd-intercalated lamellar MXene membrane to modify the surface chemical properties (H-spillover effect) of MXene (Ti 3 C 2 T x ) and to expand the interlayer spacing (from 2.29 to 3.26 Å) due to the strong interaction between Pd 2+ and MXene nanosheets with negative charge. Here, we performed a single-step etching approach to prepare 2D Pd-MXene membrane and demonstrated its excellent H 2 permeability of 2.66 × 10 −7 mol m −2 s −1 ·Pa −1 and H 2 /CO 2 selectivity of 242 at 25 °C, which greatly exceeds the current benchmark membranes. We also developed single gas transport mathematical mechanism models to interpret and support the experimental results. The combined experimental and modeling results show that interlayer spacing and H-spillover effect of Pd-MXene membrane benefit H 2 /CO 2 separation.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2016
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IF 3.958
Huan Chen,Ting Li,Fang Jiang,Zhe Wang
Catalytic reduction of N -nitrosodimethylamine (NDMA) was investigated over γ-Al 2 O 3 supported bimetallic Pd-Ni catalysts (3%(Pd x Ni 1−x )). NDMA could be reduced to dimethylamine over 3%(Pd 0.8 Ni 0.2 ) with a metal-loading-normalized pseudo-first-order rate constant of 836 ± 21 L g me −1 h −1 . Characterization results showed that the reducibility of PdO (or NiO) was improved by addition of Ni (or Pd) in 3%(Pd x Ni 1−x ); Pd-Ni ensembles were formed in 3%(Pd x Ni 1−x ) and there was an electronic transfer from Pd to Ni; metal dispersion was affected by the formation of Pd-Ni ensembles and a volcano curve of metal dispersion via Pd/Ni ratio was observed. The activity profiles demonstrated that TOF had a significant positive relationship with metal dispersion of 3%(Pd x Ni 1−x ), indicating high metal dispersion favor NDMA reduction. NDMA reduction over 3%(Pd 0.8 Ni 0.2 ) catalyst could be described by Langmuir-Hinshelwood model, reflecting an adsorption controlled reduction mechanism. The reduction mechanism of NDMA over 3%(Pd 0.8 Ni 0.2 ) catalyst was proposed to be that H 2 was activated by Pd, and H spillover from Pd to Ni/NiO reduced NDMA though N-N cleavage.
研究领域:
环境科学
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化学工程
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催化
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产品关联
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
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IF 16.6
Mao Qiqi,Mu Xu,Wang Wenxin,Deng Kai,Yu Hongjie,Wang Ziqiang,Xu You,Wang Liang,Wang Hongjing
Organic electrocatalytic conversion is an essential pathway for the green conversion of low-cost organic compounds to high-value chemicals, which urgently demands the development of efficient electrocatalysts. Here, we report a Cu single-atom dispersed Rh metallene arrays on Cu foam for cathodic nitrobenzene electroreduction reaction and anodic methanol oxidation reaction. In the coupled electrocatalytic system, the Cu single-atom -Rh metallene arrays on Cu foam requires only the low voltages of 1.18 V to reach current densities of 100 mA cm −2 for generating aniline and formate, with up to ~100% of nitrobenzene conversion/ aniline selectivity and over ~90% of formate Faraday efficiency, achieving synthesis of high-value chemicals. Density functional theory calculations reveal the electron effect between Cu single-atom and Rh host and catalytic reaction mechanism. The synergistic catalytic effect and H*-spillover effect can improve catalytic reaction process and reduce energy barrier for reaction process, thus enhancing electrocatalytic reaction activity and target product selectivity.
研究领域:
化学工程
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电化学
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催化
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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