Surface and interface design for heterogeneous catalysis

2019 ◽  
Vol 21 (2) ◽  
pp. 523-536 ◽  
Author(s):  
Weixin Huang ◽  
Wei-Xue Li

Recent progresses in catalytic nanocrystals with uniform and well-defined structures, in situ characterization techniques, and theoretical calculations are facilitating the innovation of efficient catalysts via surface and interface designs, including crystal phase design, morphology/facet design, and size design, followed by controlled synthesis.

Author(s):  
Xianghong Tong ◽  
Oliver Pohland ◽  
J. Murray Gibson

The nucleation and initial stage of Pd2Si crystals on Si(111) surface is studied in situ using an Ultra-High Vacuum (UHV) Transmission Electron Microscope (TEM). A modified JEOL 200CX TEM is used for the study. The Si(111) sample is prepared by chemical thinning and is cleaned inside the UHV chamber with base pressure of 1x10−9 τ. A Pd film of 20 Å thick is deposited on to the Si(111) sample in situ using a built-in mini evaporator. This room temperature deposited Pd film is thermally annealed subsequently to form Pd2Si crystals. Surface sensitive dark field imaging is used for the study to reveal the effect of surface and interface steps.The initial growth of the Pd2Si has three stages: nucleation, growth of the nuclei and coalescence of the nuclei. Our experiments shows that the nucleation of the Pd2Si crystal occurs randomly and almost instantaneously on the terraces upon thermal annealing or electron irradiation.


2021 ◽  
Vol 9 (12) ◽  
pp. 7556-7565
Author(s):  
Guojian Chen ◽  
Yadong Zhang ◽  
Ke Liu ◽  
Xiaoqing Liu ◽  
Lei Wu ◽  
...  

Constructing phenanthroline-based cationic radical porous hybrid polymers as versatile metal-free heterogeneous catalysts for both oxidation of sulfides and CO2 conversion.


2016 ◽  
Vol 45 (1) ◽  
pp. 63-82 ◽  
Author(s):  
Zhanxi Fan ◽  
Hua Zhang

In this review, the recent progress of crystal phase-controlled synthesis, properties and applications of noble metal nanomaterials is systematically introduced.


MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1637 ◽  
Author(s):  
Domonkos Tolnai ◽  
Tungky Subroto ◽  
Serge Gavras ◽  
Ricardo Buzolin ◽  
Andreas Stark ◽  
...  

Mg-4Nd base alloys with Zn additions of 3, 5 and 8 wt % were investigated with in situ synchrotron radiation diffraction during solidification. This method enabled the investigation of phase formation and transformation in the alloys. The diffraction results were supported with TEM observations on the as-solidified samples. The results show the effect of increased Zn addition on stabilizing the Mg3RE phase (RE—rare earth). The experimental results agree only partially with the theoretical calculations indicating the need to improve the existing thermodynamic database on the alloy system.


Nano Energy ◽  
2016 ◽  
Vol 27 ◽  
pp. 147-156 ◽  
Author(s):  
Chaojiang Niu ◽  
Xiong Liu ◽  
Jiashen Meng ◽  
Lin Xu ◽  
Mengyu Yan ◽  
...  

Author(s):  
Têko W. Napporn ◽  
Laetitia Dubau ◽  
Claudia Morais ◽  
Mariana R. Camilo ◽  
Julien Durst ◽  
...  

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