Catalysis by Enzymes: The Biological Ammonia Synthesis

Abstract

Enzymes are nature's own catalysts and fundamental for life, as they catalyze essentially all biological processes. Compared to inorganic catalysts, however, their structure and function is immensely more complicated. Computational . modeling has played an increasing role in elucidating enzyme mechanisms, as it can provide information complementary to experimental techniques. Elucidating enzyme structure and mechanism is not only important to understand the basic functions of life, they can also help to find and develop inorganic catalysts. In this review, an overview of recent computational developments for the enzyme nitrogenase will be given. Nitrogenase catalyzes ammonia synthesis, which is also a very important reaction in inorganic catalysis, and insight on enzyme structure and function could provide understanding on how to design biomimetic catalysts for low temperature ammonia synthesis.

Is Nanostructuring Sufficient To Get Catalytically Active Au?

“…Enzymes are neither homogeneous nor heterogeneous catalysts, but sometimes in between. They are extremely efficient catalysts, for example nitrogenase enzymes convert nitrogen from the air to ammonia at ambient temperature [3], while the Haber-Bosch process requires temperature above 400 °C [4,5]. Biocatalysts occur widely in our life.…”

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species NxHy

“…[25][26][27][28][29] This mechanism features a strictly alternating sequence of protonation and reduction of the N-N bond, proceeding through diazenido (N 2 H -), diazene (N 2 H 2 ), hydrazido (N 2 H 3 -), and hydrazine (N 2 H 4 ) intermediates before N-N bond cleavage in course of the fifth hydrogenation (Figure 2). The fact that diazene and hydrazine have been shown to represent substrates of nitrogenase provides further support for this mechanism.…”

Predicting Catalysis: Understanding Ammonia Synthesis from First-Principles Calculations

“…It has been hypothesized that one part of the enzyme functions just like a battery. 142 The reaction mechanisms in the industrial and the enzymatic synthesis differ significantly. In the enzyme, N 2 molecules are hydrogenated, 60 while, in the Haber-Bosch method, the strong N 2 triple bonds as well as the H 2 bonds are cleaved before nitrogen and hydrogen atoms on the metal surface can react, so in this case, it is the N atoms which are hydrogenated.…”