Metal macrocyclics, electrocatalytic properties

Phthalocyanine complexes are organic macrocycles with 18 7t-electrons, structurally resembling the naturally-occuring porphyrins complexes [1-3], Electrodes modified with transition metal (notably Fe, Co, Mn, Ni) phthalocyanine (MPc, Fig.l) complexes have continued to generate immense research interests because of their well-established electrocatalytic properties [3-6],... 

The effects of pyrolysis on the electrocatalytic properties of the same three macrocycles dispersed in Vulcan XC-72 for 02 reduction were examined using thin porous electrodes applied to the carbon disk of an RRD E as sembly. Steady state polarization curves obtained at co = 2500 rpminO.l M NaOH and 0.05 M H2S04are shown in Figures 3.70 and 3.71. As is evident from the results presented therein, the activity of H2TMPP in both media (see solid squares) before and after pyrolysis was much lower than that of the metallated counterparts and fairly close to that of... 

Many routes have been followed to use these organic conducting polymers as host matrices for the incorporation of various types of ionic or molecular species, which possessed promising electrocatalytic properties. These include metallic particles, metallic oxides, metal complexes, transition metal macrocycles, depending on the electrochemical reaction to be catalysed. 

Nykong et al. have also smdied a variety of cobalt containing macrocycles. The electrocatalytic properties of cyanocobalamin adsorbed onto GCEs in aqueous solution was examined Along with adsorbed cobalt(II) tetrasulfonated ph-thalocyanine (Co(TSPc)) ", adsorbed cobalt phthalocyanine is examined (CoPc) in DMSO ". The proposed mechanism invokes both a ring- and metal-centered reduction during NO catalysis, Eqs. (4.35)-(4.39). 

Fundamental Studies on the Electrocatalytic Properties of Metal Macrocyclics and Other Complexes for the Electroreduction of O2... 

Chapters 7-12 focus on the electrocatalysis of carbon-based non-precious metal catalysts. The unique properties and fuel cell applications of various carbon based catalysts are intensively discussed in these chapters. Chapter 7 summarizes the fundamental studies on the electrocatalytic properties of metallomacrocyclic and other non-macrocyclic complexes. Chapter 8 and 9 review the progress made in the past 5 years of pyrolyzed carbon-supported nitrogen-coordinated transition metal complexes. Chapter 10 gives a comprehensive discussion on the role of transitional metals in the ORR electrocatalysts in acidic medium. Chapter 11 introduces modeling tools such as density functional theory (DPT) and ah initio molecular dynamics (AIMD) simulation for chemical reaction studies. It also presents a theoretical point of view of the ORR mechanisms on Pt-based catalysts, non-Pt metal catalysts, and non-precious metal catalysts. Chapter 12 presents an overview on recent progresses in the development of carbon-based metal-free ORR electrocatalysts, as well as the correlation between catalyst structure and their activities. 

Chapter 13 and 14 summarize the development of transitional metal oxides and transition metal chalcogenides for ORR, respectively. Chapter 15 is the only chapter in this book dedicated to the ORR catalysis of alkaline fuel cells. Electrocatalytic properties of various non-Pt catalysts including Ag, Pd, transition metal macrocycles, metal oxides, and multifunctional materials are presented. Fundamental issues related to the design of low-cost, high-performance electrocatalysts for alkaline fuel cells are discussed. Chapter 16 and 17 review the recent advances on the study of ORR on Au and Pd-based catalysts, respectively. 

---