Improved catalytic performance of Co-MOF-74 by nanostructure construction

2020 ◽  
Vol 22 (18) ◽  
pp. 5995-6000
Author(s):  
Fanyu Zhang ◽  
Jianling Zhang ◽  
Bingxing Zhang ◽  
Lirong Zheng ◽  
Xiuyan Cheng ◽  
...  

We demonstrate the construction of hollow structural Co-MOF-74, with a shell as thin as ∼50 nm, assembled by nanoparticles. Co-MOF-74 exhibits high performance for the photocatalytic oxidation of thioanisole and thermocatalytic cyanosilylation of aldehydes.

2017 ◽  
Vol 4 (7) ◽  
pp. 1173-1181 ◽  
Author(s):  
Haidong Yang ◽  
Sha Luo ◽  
Yun Bao ◽  
Yutong Luo ◽  
Jun Jin ◽  
...  

The ultrathin Ni70Fe30LDH nanosheets were successfullyin situgrown on anodic polarized copper foil, denoted as u-Ni70Fe30LDHs/a-CF. Benefiting from the ultrathin nanosheet structure, the catalyst exhibits remarkable catalytic performance for OER in 1 M KOH solution.


2013 ◽  
Vol 740 ◽  
pp. 565-569
Author(s):  
Xiao Xiao Meng ◽  
Mao Xiang Jing ◽  
Feng Lin He ◽  
Xiang Qian Shen

The catalysts La0.8K0.2FeO3(LKFO), La0.8K0.2Fe0.7Mn0.3O3(LKFMO) and La0.8K0.2Fe0.67Mn0.3Pt0.03O3(LKFMPO) were prepared by the citrate-gel process and the catalyst-coated honeycomb ceramic devices were prepared by the citrate-gel assisted dip-coating method. All the catalysts have a high performance on the simultaneous removal of NOxand soot at a temperature range of 200 to 400°C under the practical diesel exhaust emission. The obvious catalytic improvement is largely due to the effects of ions substitution, pore structure and microstructural characteristics of the catalysts. The catalytic performance order is LKFMPO > LKFMO > LKFO. Among them the LKFMPO catalyst shows the best catalytic properties, especially in the removal of NOx, with a maximum conversion rate of NOx(21.2%).


2018 ◽  
Vol 8 (3) ◽  
pp. 806-816 ◽  
Author(s):  
Shaohua Xie ◽  
Yuxi Liu ◽  
Jiguang Deng ◽  
Jun Yang ◽  
Xingtian Zhao ◽  
...  

The adsorbed o-xylene species can immediately react with active oxygen species at the highly active Pd–CoO interface between Pd NPs and meso-CoO, thus resulting in good catalytic performance of Pd/meso-CoO for o-xylene catalytic combustion.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Asghari ◽  
Mohammadreza Khanmohammadi Khorrami ◽  
Sayed Habib Kazemi

AbstractThe present work introduces a good prospect for the development of hierarchical catalysts with excellent catalytic performance in the methanol to aromatic hydrocarbons conversion (MTA) process. Hierarchical H-ZSM5 zeolites, with a tailored pore size and different Si/Al ratios, were synthesized directly using natural kaolin clay as a low-cost silica and aluminium resource. Further explored for the direct synthesis of hierarchical HZSM-5 structures was the steam assisted conversion (SAC) with a cost-effective and green affordable saccharide source of high fructose corn syrup (HFCS), as a secondary mesopore agent. The fabricated zeolites exhibiting good crystallinity, 2D and 3D nanostructures, high specific surface area, tailored pore size, and tunable acidity. Finally, the catalyst performance in the conversion of methanol to aromatic hydrocarbons was tested in a fixed bed reactor. The synthesized H-ZSM5 catalysts exhibited superior methanol conversion (over 100 h up to 90%) and selectivity (over 85%) in the methanol conversion to aromatic hydrocarbon products.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xi Zhang ◽  
Guoqing Cui ◽  
Haisong Feng ◽  
Lifang Chen ◽  
Hui Wang ◽  
...  

AbstractSelective hydrogenolysis of biomass-derived glycerol to propanediol is an important reaction to produce high value-added chemicals but remains a big challenge. Herein we report a PtCu single atom alloy (SAA) catalyst with single Pt atom dispersed on Cu nanoclusters, which exhibits dramatically boosted catalytic performance (yield: 98.8%) towards glycerol hydrogenolysis to 1,2-propanediol. Remarkably, the turnover frequency reaches up to 2.6 × 103 molglycerol·molPtCu–SAA−1·h−1, which is to our knowledge the largest value among reported heterogeneous metal catalysts. Both in situ experimental studies and theoretical calculations verify interface sites of PtCu–SAA serve as intrinsic active sites, in which the single Pt atom facilitates the breakage of central C–H bond whilst the terminal C–O bond undergoes dissociation adsorption on adjacent Cu atom. This interfacial synergistic catalysis based on PtCu–SAA changes the reaction pathway with a decreased activation energy, which can be extended to other noble metal alloy systems.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiuping Han ◽  
Binghua Yao ◽  
Keying Li ◽  
Wenjing Zhu ◽  
Xuyuan Zhang

The use of sunlight for photocatalytic oxidation is an ideal strategy, but it is limited by factors such as insufficient light absorption intensity of the photocatalyst and easy recombination of photogenerated electron holes. TiO2 is favored by researchers as an environment-friendly catalyst. In this paper, TiO2 is combined with WO3 to obtain a nanofiber with excellent catalytic performance under sunlight. The WO3/TiO2 composite nanofibers were synthesized by using the electrospinning method. The X-ray diffraction (XRD) analysis indicated that WO3 was successfully integrated onto the surface of TiO2. The photodegradation performance and photocurrent analysis of the prepared nanofibers showed that the addition of WO3 really improved the photocatalytic performance of TiO2 nanofibers, methylene blue (MB) degradation rate increased from 72% to 96%, and 5% was the optimal composite mole percentage of W to Ti. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectra (UV-Vis DRS), and Brunauer-Emmett-Teller (BET) analysis further characterized the properties of 5% WO3/TiO2 nanofibers. The H2 generation rate of 5% WO3/TiO2 nanofibers was 107.15 μmol·g−1·h−1, in comparison with that of TiO2 nanofibers (73.21 μmol·g−1·h−1) under the same condition. The 5% WO3/TiO2 produced ·OH under illumination, which played an important role in the MB degradation. Also, the enhanced photocatalytic mechanism was also proposed based on the detailed analysis of the band gap and the active species trapping experiment. The results indicated that the effective separation of Z-scheme photogenerated electron-hole pairs and transfer system constructed between TiO2 and WO3 endowed the excellent photocatalytic activity of 5% WO3/TiO2 nanofibers.


2020 ◽  
Vol 89 (1) ◽  
pp. 10103
Author(s):  
Honglin Li ◽  
Yuting Cui ◽  
Haijun Luo ◽  
Wanjun Li

Efforts to efficiently use of the next generation 2-dimension (2D) structured monolayers is getting a lot of attention for their excellent properties recently. In this work, we composite the blue phosphorus (BP) and monolayer GeX (X = C/H/Se) via van der Waals force (vdW) interaction to obtain well defined type-II band alignment heterostructures. A systematic theoretic study is conducted to explore the interlayer coupling effects and the bands re-alignment of BP-GeX (X = C/H/Se) heterostructure after the strain imposed. To devise usable and efficient materials to degrade pollutant or used as a potential photovoltaic cell material, previous researches have proved that using 2D materials as components is a feasible way to obtain high performance. Here, we prudently present a comprehensive investigation on the BP and GeX (X = C/H/Se) with different twisted angles via first-principles calculation to lay a theoretical framework on the band alignment and carriers' separation. It reveals that the intrinsic electronic properties of BP and GeX are roughly preserved in the corresponding heterostructures. Upon strain applied, band alignment can be flexibly manipulated by varying external imposed strain. The heterostructures can maintain type-II character within a certain strain range, and thus the carriers are spatially separated to different portions. This work not only provides a deep insight into the construction of the heterostructure, but presents a new possibility to search for a flexible and feasible approach to promote its catalytic performance. The corresponding results would provide meaningful guidelines for designing 2D structure based novel materials.


Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1612
Author(s):  
Zhaoyu Wen ◽  
Qiong Fu ◽  
Jie Wu ◽  
Guangyin Fan

Simple and efficient synthesis of a nano-catalyst with an excellent catalytic property for hydrogen generation from hydrolysis of dimethyl amine-borane (DMAB) is a missing piece. Herein, effective and recycled palladium (Pd) nanoparticles (NPs) supported on soft nitriding porous carbon (NPC) are fabricated and applied for DMAB hydrolysis. It is discovered that the soft nitriding via a low-temperature urea-pretreatment induces abundant nitrogen-containing species on the NPC support, thus promoting the affinity of the Pd precursor and hindering the agglomeration of formed Pd NPs onto the NPC surface during the preparation process. Surface-clean Pd NPs with a diameter of sub-2.0 nm deposited on the NPC support (Pd/NPC) exhibit an outstanding catalytic performance with a turnover frequency (TOF) of 2758 h−1 toward DMAB hydrolysis, better than many previous reported Pd-based catalysts. It should be emphasized that the Pd/NPC also possesses a good stability without an obvious decrease in catalytic activity for DMAB hydrolysis in five successive recycling runs. This study provides a facile but efficient way for preparing high-performance Pd catalysts for catalytic hydrogen productions.


RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 82370-82375 ◽  
Author(s):  
Shangfeng Jiang ◽  
Baolian Yi ◽  
Qing Zhao ◽  
Hongjie Zhang ◽  
Yang Su ◽  
...  

Here, we present a novel MOR anode catalyst based on TiN nanorod arrays with high performance towards MOR.


2019 ◽  
Author(s):  
Di Li

Plasmon mediated photocatalysis provides a novel strategy for harvesting solar energy. Identification of rate determining step and its activation energy in plasmon mediated photocatalysis plays critical roles for understanding the contribution of hot carriers that facilitates rational designing catalysts with integrated high photo-chemical conversion efficiency and catalytic performance. However, it remains a challenge due to a lack of research tools with spatiotemporal resolution that capable of capturing intermediates. In this work, we used a single molecular fluorescence approach to investigate a localized surface plasmon resonance (LSPR) enhanced photocatalytic reaction with sub-turnover resolution. By introducing variable temperature as an independent parameter in plasmonic photocatalysis, the activation energies of tandem reaction steps, including intermediate generation, product generation and product dissociation, were clearly differentiated, and intermediates generation was found to be the rate-limiting step. Remarkably, the cause of plasmon enhanced catalysis performance was found to be its ability of lowering the activation energy of intermediates generation. This study gives new insight into the photo-chemical energy conversion pathways in plasmon enhanced photocatalysis and sheds light on designing high performance plasmonic catalysts.


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