Transition metal nitrogen- containing

Pt-based catalysts are two necessary approaches at the current technology stage. It is believed that non-noble metal electrocatalysts is probably the sustainable solution for PEM fuel cell commercialization. In the past several decades, various nonnoble metal catalysts for ORR have been explored, including non-pyrolyzed and pyrolyzed transition metal nitrogen-containing complexes, transition metal chalcogenides, conductive polymer-based catalysts, metal oxides/carbides/nitrides/ oxynitrides/carbonitrides, and enzymatic compoimds. The major effort in non-noble metal electrocatalysts for ORR is to increase both the catalytic activity and stability. 

Figure 8.9 Structure of MnMoN2 and j3-MnWN2. Examples of ternary transition metal nitrides containing octahedral manganese and trigonal prismatic molybenum/tungsten. Small white = Manganese, Black = Molybenum/Tungsten, Large white = Nitrogen.

The study of catenated nitrogen ligands has been extended to N5 systems by the synthesis of transition metal complexes containing coordinated 1,5-diarylpentaza-l,4-diene-3-ide anions (6). Although substituted pentaza-1,4-... 

XVI. Transition Metal Complexes Containing Other Ligands with Nitrogen,... 

Transition metal complexes containing coordinated small molecules such as CO, 02, and N2 have been known for many decades and are of critical importance in industrial and biological processes and coordination chemistry as a whole (Table 1.1). Of all the industrially relevant molecules, H2 is arguably the most important. Catalytic hydrogenation reactions represent the most massive man-made chemical reactions in the world All crude oil is treated with hydrogen to remove sulfur and nitrogen in hydrodesulfurization/hydrodenitrogenation processes. Ten billion tons of ammonia is produced worldwide by the Haber process ... 

The real understanding of this multivariable process is still not clear. The ideal situation should be a synthesis process, based on the use of reagents containing a transition metal, nitrogen, and carbon, whose parameters should be controlled to produce a homogenous catalyst. Unfortunately, according to the current state of the art, the synthesis process is still a difficult task. 

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