scholarly journals Single‐Atom Catalysis: Sustainable Synthesis of Bimetallic Single Atom Gold‐Based Catalysts with Enhanced Durability in Acetylene Hydrochlorination (Small 16/2021)

Small ◽  
2021 ◽  
Vol 17 (16) ◽  
pp. 2170071
Author(s):  
Selina K. Kaiser ◽  
Adam H. Clark ◽  
Lucrezia Cartocci ◽  
Frank Krumeich ◽  
Javier Pérez‐Ramírez
Keyword(s):  
Single Atom ◽  
Acetylene Hydrochlorination

Single-Atom AuI–N3 Site for Acetylene Hydrochlorination Reaction

ACS Catalysis ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 1865-1870 ◽  
Author(s):  
Zheng Chen ◽  
Yinjuan Chen ◽  
Songlin Chao ◽  
Xiaobin Dong ◽  
Wenxing Chen ◽  
...  
Keyword(s):  
Single Atom ◽  
Acetylene Hydrochlorination

Single-Atom Ruthenium Catalytic Sites for Acetylene Hydrochlorination

2021 ◽  
pp. 7350-7356
Author(s):  
Hongyu Zhang ◽  
Tiantong Zhang ◽  
Yiming Jia ◽  
Jinli Zhang ◽  
You Han
Keyword(s):  
Single Atom ◽  
Acetylene Hydrochlorination ◽  
Catalytic Sites

scholarly journals Single-Atom X/g-C3N4(X = Au1, Pd1, and Ru1) Catalysts for Acetylene Hydrochlorination: A Density Functional Theory Study

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 808 ◽  
Author(s):  
Zhou ◽  
Zhu ◽  
Kang
Keyword(s):  
Density Functional Theory ◽  
Energy Barrier ◽  
Density Functional ◽  
Single Atom ◽  
Functional Theory ◽  
Acetylene Hydrochlorination ◽  
B3lyp Method ◽  
The Density Functional Theory ◽  
Catalytic Mechanisms ◽  
Functional Dispersion

The mechanisms of the single-atom X/g-C3N4(X = Au1, Pd1, and Ru1) catalysts for the acetylene hydrochlorination reaction were systematically investigated using the density functional theory (DFT) B3LYP method. The density functional dispersion correction obtained by the DFT-D3 method was taken into account. During the reaction, C2H2 and HCl were well activated and the analysis of the adsorption energy demonstrated the adsorption performance of C2H2 is better than that of HCl. The catalytic mechanisms of the three catalysts consist of one intermediate and two transition states. Moreover, our results showed that the three single-atom catalysts improve the catalytic activity of the reaction to different degrees. The calculated energy barrier declines in the order of Pd1/g-C3N4 > Ru1/g-C3N4 > Au1/g-C3N4, and the energy barrier for the Au1/g-C3N4 catalyst was only 13.66 kcal/mol, proving that single-atom Au1/g-C3N4 may be a potential catalyst for hydrochlorination of acetylene to vinyl chloride.

Single-Site Au/Carbon Catalysts with Single-Atom and Au Nanoparticles for Acetylene Hydrochlorination

2020 ◽  
Vol 3 (3) ◽  
pp. 3004-3010 ◽  
Author(s):  
Guojun Lan ◽  
Qingfeng Ye ◽  
Yihan Zhu ◽  
Haodong Tang ◽  
Wenfeng Han ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Single Site ◽  
Single Atom ◽  
Acetylene Hydrochlorination ◽  
Carbon Catalysts

Sustainable Synthesis of Bimetallic Single Atom Gold‐Based Catalysts with Enhanced Durability in Acetylene Hydrochlorination

Small ◽  
2021 ◽  
pp. 2004599
Author(s):  
Selina K. Kaiser ◽  
Adam H. Clark ◽  
Lucrezia Cartocci ◽  
Frank Krumeich ◽  
Javier Pérez‐Ramírez
Keyword(s):  
Single Atom ◽  
Acetylene Hydrochlorination

scholarly journals Design of carbon supports for metal-catalyzed acetylene hydrochlorination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Selina K. Kaiser ◽  
Ivan Surin ◽  
Ana Amorós-Pérez ◽  
Simon Büchele ◽  
Frank Krumeich ◽  
...  
Keyword(s):  
Industrial Process ◽  
Catalytic Performance ◽  
Single Atom ◽  
Catalyst Stability ◽  
Carbon Supports ◽  
Acetylene Hydrochlorination ◽  
Active Metal ◽  
Central Activity ◽  
Metal Nanostructure ◽  
Metal Catalyzed

AbstractFor decades, carbons have been the support of choice in acetylene hydrochlorination, a key industrial process for polyvinyl chloride manufacture. However, no unequivocal design criteria could be established to date, due to the complex interplay between the carbon host and the metal nanostructure. Herein, we disentangle the roles of carbon in determining activity and stability of platinum-, ruthenium-, and gold-based hydrochlorination catalysts and derive descriptors for optimal host design, by systematically varying the porous properties and surface functionalization of carbon, while preserving the active metal sites. The acetylene adsorption capacity is identified as central activity descriptor, while the density of acidic oxygen sites determines the coking tendency and thus catalyst stability. With this understanding, a platinum single-atom catalyst is developed with stable catalytic performance under two-fold accelerated deactivation conditions compared to the state-of-the-art system, marking a step ahead towards sustainable PVC production.

Single Atom Image Contrast in Fixed Beam Dark Field Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 366-367
Author(s):  
Wah Chi
Keyword(s):  
Scattering Amplitude ◽  
Present Report ◽  
Dark Field ◽  
Image Contrast ◽  
Single Atom ◽  
Optical Theorem ◽  
Hartree Fock ◽  
Heavy Atoms ◽  
Beam Stop ◽  
Fixed Beam

Resolution and contrast are the important factors to determine the feasibility of imaging single heavy atoms on a thin substrate in an electron microscope. The present report compares the atom image characteristics in different modes of fixed beam dark field microscopy including the ideal beam stop (IBS), a wire beam stop (WBS), tilted illumination (Tl) and a displaced aperture (DA). Image contrast between one Hg and a column of linearly aligned carbon atoms (representing the substrate), are also discussed. The assumptions in the present calculations are perfectly coherent illumination, atom object is represented by spherically symmetric potential derived from Relativistic Hartree Fock Slater wave functions, phase grating approximation is used to evaluate the complex scattering amplitude, inelastic scattering is ignored, phase distortion is solely due to defocus and spherical abberation, and total elastic scattering cross section is evaluated by the Optical Theorem. The atom image intensities are presented in a Z-modulation display, and the details of calculation are described elsewhere.

Atomic Spectroscopy in the FIM

1986 ◽  
Vol 44 ◽  
pp. 758-761
Author(s):  
J. J. Hren ◽  
S. D. Walck
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Atom Probe ◽  
Atomic Spectroscopy ◽  
Single Atom ◽  
Statistical Sampling ◽  
Commercial Instrument ◽  
Available Technology ◽  
High Electric Fields ◽  
Field Ion Microscope

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.

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