Heterogeneous catalysts from organometallic precursors: how to design isolated, stable and active sites. Applications to zirconium catalyzed organic reactions

Author(s):  
A. Choplin ◽  
B. Coutant ◽  
C. Dubuisson ◽  
P. Leyrit ◽  
C. McGill ◽  
...  
Author(s):  
Alexis T. Bell

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.


2021 ◽  
Vol 50 (13) ◽  
pp. 4445-4469
Author(s):  
Jimmy Nelson Appaturi ◽  
Rajni Ratti ◽  
Bao Lee Phoon ◽  
Samaila Muazu Batagarawa ◽  
Israf Ud Din ◽  
...  

One of the most crucial attributes of synthetic organic chemistry is to design organic reactions under the facets of green chemistry for the sustainable production of chemicals.


Author(s):  
Jeffrey D. Rimer ◽  
Aseem Chawla ◽  
Thuy T. Le

Crystal engineering relies upon the ability to predictively control intermolecular interactions during the assembly of crystalline materials in a manner that leads to a desired (and predetermined) set of properties. Economics, scalability, and ease of design must be leveraged with techniques that manipulate the thermodynamics and kinetics of crystal nucleation and growth. It is often challenging to exact simultaneous control over multiple physicochemical properties, such as crystal size, habit, chirality, polymorph, and composition. Engineered materials often rely upon postsynthesis (top-down) processes to introduce properties that would otherwise be challenging to attain through direct (bottom-up) approaches. We discuss the application of crystal engineering to heterogeneous catalysts with a focus on four general themes: ( a) tailored nanocrystal size, ( b) controlled environments surrounding active sites, ( c) tuned morphology with well-defined facets, and ( d) hierarchical materials with disparate pore size and active site distributions. We focus on nonporous materials, including metals and metal oxides, and two classes of porous materials: zeolites and metal organic frameworks. We review novel synthesis methods involving synergistic experimental and computational design approaches, the challenges facing catalyst development, and opportunities for future advancement in crystal engineering.


2020 ◽  
Vol 10 (11) ◽  
pp. 1902106 ◽  
Author(s):  
Rahman Daiyan ◽  
Wibawa Hendra Saputera ◽  
Hassan Masood ◽  
Josh Leverett ◽  
Xunyu Lu ◽  
...  

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