Homogeneous catalysis Electrocatalysis

Investigation of carbon dioxide catalytic activation is explored by a variety of subdisciplines (homogeneous catalysis, heterogeneous catalysis, electrocatalysis/photoelectrocatalysis), often with little cross-citation of work. This situation created a need to bring together the leading researchers to provide an overview of methods and accomplishments to date. 

In addition to the synthesis of specific ligands and the resulting catalysts new ideas and concepts begin to combine with transition metal chemistry to open up new areas in homogeneous catalysis, like catalysis under supercritical conditions, colloidal catalysis , organometallic electrocatalysis and multi-metallic catalysis " ( cooperative catalysis ). 

The metal oxo unit (M=0) is a fundamental constituent of both soluble molecular clusters and of complex solid materials. The practical interest in the molecular species reflects applications to homogeneous catalysis, heterogeneous catalysis, photocatalysis, electrocatalysis, magnetic materials, and materials synthesis. Likewise, the solid metal oxides exhibit a remarkable range of properties, with applications to high-temperature ferroelectrics, frequency doubling nonlinear optics, electrode materials in solid-state batteries, high-temperature superconductors, catalysis, sorption, and ceramics. 

Catalysis (from the greek kata = down and lyein = loosen) can be divided into areas such as homogeneous, heterogeneous, bio-, photo-, and electrocatalysis (Figure 2.1-2, Table 2.1-1). 

In recent years, much attention has been focused on electrochemical studies of metalloporphyrins, not only as mimetic compounds of the iron porphyrin unit in heme proteins but also as potential electrocatalysts . Metalloporphyrins have been found to be applicable in both homogeneous and heterogeneous catalysis - and, because oxygen can be reduced directly through a 4-electron pathway on some transition metal porphyrins, catalysis in the heterogeneous electrochemical oxygen reduction reaction has received particular attention The application of metalloporphyrins to heterogeneous electrocatalysis requires their attachment to solid electrodes which can be realized based on chemisorption, chemical reactions with previously functionalized electrodes, chemical reactions with a functionalized polymer, incorporation of the porphyrin with the polymer film and electrochemical polymerization. 

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