Abstract
A new catalyst based on the formation of carbon supported "CoN 4" structures by heat treatment of Co(CH3COO) 2 and imidazole impregnated carbon black is introduced. The performance of the new catalyst is compared to the performance of other catalysts including activated carbon powder, granular activated carbon, and pyrolysed cobalt(II) mesotetra-4-methoxyphenylporphyrin. The optimized form of the new catalyst outperforms all these catalysts. The underlying concept is borrowed from fuel cell technology, which uses electrocatalysts that activate triplet dioxygen and facilitate its reduction. The same concept is used to reduce oxygen by hydrogen sulfide. In electrochemistry oxygen reduction is carried out by heterogeneous electron transfer, whereas in dehydrosulfurization the reduced sulfur moieties serve as the electron donors. We postulate that the reason for the improved performance of the new catalyst compared to pyrolysed carbon supported cobalt porphyrin, which is also a Me-N4 type catalyst, stems from the ability to load a larger amount of cobalt chelates rather than from a change of oxidation mechanism.
Original language | English |
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Pages (from-to) | 296-304 |
Number of pages | 9 |
Journal | Applied Catalysis B: Environmental |
Volume | 63 |
Issue number | 3-4 |
DOIs | |
State | Published - 31 Mar 2006 |
Bibliographical note
Funding Information:We thankfully acknowledge the financial help of the BMBF Germany—MOS Israel Water Technology Program, the Israel Science Foundation and Mekorot Ltd. F.G. and I.E. thank the Valazzi-Pikovsky Fellowship Fund. The financial support of the Israel Science Foundation is gratefully acknowledged.
Keywords
- Carbon supported catalyst
- Cobalt porphyrin
- Drinking water
- Hydrogen sulfide
- Me-N
- Oxidation