Process/catalyst development reaction mechanism

Development of powerful spectroscopy and microscopy techniques, which allow us to study underlying chemical transformations that govern the performance of catalysts, including reaction mechanisms and the evolution of catalyst structure, with high spatial and temporal resolutions and at relevant conditions [2-6]. Development of density functional theory (DFT) methodology, which is utilized to study chemical transformations at the elementary step level with reasonable accuracy and efficiency [7]. DFT is particularly well suited for the treatment of extended metallic structures, which are often ideal model systems for heterogeneous catalytic processes [8-11]. 

The subjects of catalytic science include catalysis (cataljAic phenomena and principle) catalyst (composition, structure, performance and manufacturing method and principle) catalytic reaction kinetics (chemical kinetics and mechanism) as well as cataljAic reaction engineering (apparent kinetics inclucing transport process and reaction process and reactor design) etc. The main tasks of catalytic science are to elucidate the nature of catalytic active sites, the function of catalyst and reaction mechanism to explore the main factors influencing activity, selectivity and stabihty of catalyst to accumulate acknowledge for the exploitation and development of chemical catalysis and to open up its relatively new disciplines — bionic catalysis, photo catalysis, electro catalysis and photoelectric catalysis — to indicate... 

In this work, a detailed kinetic model for the Fischer-Tropsch synthesis (FTS) has been developed. Based on the analysis of the literature data concerning the FT reaction mechanism and on the results we obtained from chemical enrichment experiments, we have first defined a detailed FT mechanism for a cobalt-based catalyst, explaining the synthesis of each product through the evolution of adsorbed reaction intermediates. Moreover, appropriate rate laws have been attributed to each reaction step and the resulting kinetic scheme fitted to a comprehensive set of FT data describing the effect of process conditions on catalyst activity and selectivity in the range of process conditions typical of industrial operations. 

The technology and chemistry of isoalkane-alkene alkylation have been thoroughly reviewed for both liquid and solid acid catalysts (15) and for solid acid catalysts alone (16). The intention of this review is to provide an up-to-date overview of the alkylation reaction with both liquid and solid acids as catalysts. The focus is on the similarities and differences between the liquid acid catalysts on one hand and solid acid catalysts, especially zeolites, on the other. Thus, the reaction mechanism, the physical properties of the individual catalysts, and their consequences for successful operation are reviewed. The final section is an overview of existing processes and new process developments utilizing solid acids. 

The EM studies show that the novel glide shear mechanism in the solid state heterogeneous catalytic process preserves active acid sites, accommodates non-stoichiometry without collapsing the catalyst bulk structure and allows oxide catalysts to continue to operate in selective oxidation reactions (Gai 1997, Gai et al 1995). This understanding of which defects make catalysts function may lead to the development of novel catalysts. Thus electron microscopy of VPO catalysts has provided new insights into the reaction mechanism of the butane oxidation catalysis, catalyst aging and regeneration. 

T he six years since the first Advances in Chemistry Series volume, Homogeneous Catalysis—Industrial Applications and Implications, (Number 70) have been a period of mushrooming activity in the field. Not only has this activity been marked by the discovery of new types of catalysts and new insights into reaction mechanisms, but several major commercial processes based on homogeneous catalysts have been developed. 

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