Topic
Catalytic cycle
About: Catalytic cycle is a research topic. Over the lifetime, 4400 publications have been published within this topic receiving 163230 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: The crystal structure of bovine mitochondrial F1-ATPase determined at 2.8 Å resolution supports a catalytic mechanism in intact ATP synthase in which the three catalytic subunits are in different states of the catalytic cycle at any instant.
Abstract: In the crystal structure of bovine mitochondrial F1-ATPase determined at 2.8 A resolution, the three catalytic beta-subunits differ in conformation and in the bound nucleotide. The structure supports a catalytic mechanism in intact ATP synthase in which the three catalytic subunits are in different states of the catalytic cycle at any instant. Interconversion of the states may be achieved by rotation of the alpha 3 beta 3 subassembly relative to an alpha-helical domain of the gamma-subunit.
2,878 citations
TL;DR: The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance, as dehydrogenation for the production of light olefins has become extremely relevant.
Abstract: A study is conducted to demonstrate catalytic dehydrogenation of light alkanes on metals and metal oxides. The study provides a complete overview of the materials used to catalyze this reaction, as dehydrogenation for the production of light olefins has become extremely relevant. Relevant factors, such as the specific nature of the active sites, as well as the effect of support, promoters, and reaction feed on catalyst performance and lifetime, are discussed for each catalytic Material. The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance. The duration of the dehydrogenation step depends on the heat content of the catalyst bed, which decreases rapidly due to the endothermic nature of the reaction. Part of the heat required for the reaction is introduced to the reactors by preheating the reaction feed, additional heat being provided by adjacent reactors that are regenerating the coked catalysts.
1,306 citations
TL;DR: This Account introduces the energetic span model that enables one to evaluate TOFs in a straightforward manner and in affinity with the Curtin-Hammett principle, and concludes that a change in the conceptualization of catalytic cycles is in order.
Abstract: A computational study of a catalytic cycle generates state energies (the E-representation), whereas experiments lead to rate constants (the k-representation). Based on transition state theory (TST), these are equivalent representations. Nevertheless, until recently, there has been no simple way to calculate the efficiency of a catalytic cycle, that is, its turnover frequency (TOF), from a theoretically obtained energy profile. In this Account, we introduce the energetic span model that enables one to evaluate TOFs in a straightforward manner and in affinity with the Curtin−Hammett principle. As shown herein, the model implies a change in our kinetic concepts.Analogous to Ohm’s law, the catalytic chemical current (the TOF) can be defined by a chemical potential (independent of the mechanism) divided by a chemical resistance (dependent on the mechanism and the nature of the catalyst). This formulation is based on Eyring’s TST and corresponds to a steady-state regime.In many catalytic cycles, only one transi...
1,217 citations
TL;DR: In this paper, the authors explored the catalytic reduction of dinitrogen by molybdenum complexes that contain the [HIPTN3N]3- ligand.
Abstract: This Account explores the catalytic reduction of dinitrogen by molybdenum complexes that contain the [HIPTN3N]3- ligand ([HIPTN3N]3- = [(HIPTNCH2CH2)3N]3-, where HIPT = 3,5-(2,4,6-i-Pr3C6H2)2C6H3) at room temperature and pressure with protons and electrons. A total of 7−8 equiv of ammonia is formed out of ∼12 possible (depending upon the Mo derivative employed). No hydrazine is formed. Numerous X-ray studies of proposed intermediates in the catalytic cycle suggest that N2 is being reduced at a sterically protected, single Mo center operating in oxidation states between MoIII and MoVI. Subtle variations of the [HIPTN3N]3- ligand are not as successful as a consequence of an unknown shunt in the catalytic cycle that consumes reduction equivalents to yield (it is proposed) dihydrogen.
1,149 citations
TL;DR: Manganese oxidation by manganese peroxidase (MnP) was investigated, and no relationship between stimulation of enzyme activity and chelator size was found, suggesting that the substrate is free MnII rather than a MnII-chelator complex.
986 citations