Mechanochemical Activation for Resolving the Problems of Catalysis

Abstract

Plausible MCA Applications in CatalysisThe Principle Sections of Catalysis are as Follows:2.1. Development of the scientific basis of catalyst preparation. The content of this division/section is determined by its main problem, i.e. development of the methods of preparation of catalysts with the desired properties. These are: specific surface area, porous structure, phase composition, crystallization degree, morphological properties of crystals, defectiveness, dispersion, thermal stability, structural and mechanical properties, component distributions on the supports, etc. To solve the problem, one should investigate the physicochemical regularities which determine the features of synthesis and the action of materials during all stages of the method chosen for the preparation of separate families of similar materials, catalysts in our case 1) . Development of the scientific basis for prediction of catalytic actionThis section includes the most complicated and important problems, such as: ・ Chemical nature, structure and mechanism of action of active sites during operation on the catalyst surface; ・ Nature and relationships between the main and side reactions of catalytically active sites, the means and methods of influencing the above in order to increase selectivity towards the desired product;

Hallmarks of mechanochemistry: from nanoparticles to technology

“…Catalysts have been intensively investigated, and the main goal is to create general theories that would make it possible to predict the catalytic properties of solids. 4f, 14,194,[777][778][779][780][781] Nano-catalysts seem to be the next generation catalysts as they set a new paradigm in catalysis. Nano-catalysts are very promising, as they possess some of the main characteristics of the ''perfect'' catalyst, such as high dispersity (including high specific surface area) and a great core/shell ratio (which gives rise to the presence of highly active unsaturated chemical bonds).…”

“…This leads to the improvement of their catalytic properties (efficiency, lower amount of by-products and waste), prolongation of their life (deactivation and corrosion stability) and reduced catalyst cost. 14,194,[777][778][779][780][781] Catalysts are specific products and a number of requirements should be taken into account during their synthesis. Contact area, mass transfer processes and activation barriers limit the rate of chemical interactions.…”

Tribochemistry, Mechanical Alloying, Mechanochemistry: What is in a Name?

“…The attention of mechanochemical investigation soon expanded to a wide range of material types, and explored an array of phenomena including the initiation of explosives by impact and friction ( Bowden et al, 1947 ; Bowden and Gurton, 1949 ; Fox, 1975 ; Aduev et al, 1999 ), and the mechanical decomposition of polymers ( Butyagin, 1971 ; Polukhina and Baramboim, 1975 ; Oprea, 1979 ; Sohma, 1989 ; Delogu et al, 2017 ). Similarly, mechanochemical investigation into areas including the chemical processes accompanying mining, metallurgy, and the manufacturing of various oxide and chalcogenide materials became a prominent direction of research ( Senna, 1993 ; Butyagin, 1994 ; Boldyrev, 1996 ; Fernández-Bertran, 1999 ; Steinike and Tkáčová, 2000 ; Senna, 2001 ; Epelak, 2002 ; Boldyrev, 2006 ; Buyanov et al, 2009 ; Šepelák et al, 2012 ; Šepelák et al, 2013 ), expanding toward the preparation and processing of fine chemicals and pharmaceuticals ( Baba et al, 1990 ; Kuzuya et al, 1991 ; Otsuka et al, 1994 ; Dubinskaya, 1999 ; Kondo, 2000 ; Boldyrev, 2004 ; Otsuka et al, 2011 ). The 20 th century represents a period of remarkable development of the fundamental aspects of mechanochemistry and of significant progress in scaling mechanochemical reactions toward real-world industrial applications.…”

One-pot mechanochemical ball milling synthesis of the MnOx nanostructures as efficient catalysts for CO2 hydrogenation reactions

“…[34][35][36][37] The mechanochemical synthesis can be tuned by many parameters such as the milling rotation speed, the milling time, the solvent-template, the weight ratios of the milling mixtures and milling balls, the milling atmosphere, the type of mills, and additional treatments such as sonication or heat treatments as well. [38][39][40][41][42][43] The conventional dry milling method has significant drawbacks such as wider size distribution of materials, material loss, and friction. Nowadays, wet milling methods are more often used for nanomaterial synthesis.…”