Details

Autor(en) / Beteiligte

• Oldacre, Amanda N.
• Crawley, Matthew R.
• Friedman, Alan E.
• Cook, Timothy R.

Titel

Tuning the Activity of Heterogeneous Cofacial Cobalt Porphyrins for Oxygen Reduction Electrocatalysis through Self‐Assembly

Ist Teil von

• Chemistry : a European journal, 2018-08, Vol.24 (43), p.10984-10987

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2018

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• We report a suite of coordination‐driven self‐assembled prisms for heterogeneous electrocatalytic oxygen reduction (ORR) differing in the molecular clips linking two porphyrin faces in a cofacial arrangement. ORR activities and selectivities of monomeric CoTPyP along with cofacial prisms Ox‐Co, Oxa‐Co, and Benzo‐Co were probed using cyclic voltammetry and rotating ring‐disk techniques. All species were immobilized as heterogeneous catalysts on glassy carbon electrodes using a Nafion ink method. The selectivities of Ox‐Co, Oxa‐Co, and Benzo‐Co prisms towards H2O as determined by RRDE were 87, 97, and 75 %, respectively. The current density of the Oxa‐Co plateaus at five times that of Pt/C when normalized per Co/Pt. The high synthetic yield (79 %), competitive overpotential (η ≈800 mV) and high selectivity (%H2O ≈97 %) of the Oxa‐Co highlights how self‐assembly can be used to address multi‐electron multi‐proton transformations using polynuclear catalysts. Cofacial cobalt porphyrin electrocatalysts were synthesized by facile coordination‐driven self‐assembly techniques. The suite of prisms was immobilized on glassy carbon electrodes by a Nafion ink method and immediately used for heterogeneous electrocatalytic oxygen reduction (ORR). The ORR selectivities towards water as determined by rotating ring‐disk voltammetry were 75–97 %.