(376c) Engineering High Performance and Durable PGM-Free Electro-Catalysts for Oxygen Evolution Reaction in PEM Water Electrolysis
- Conference: AIChE Annual Meeting
- Year: 2017
- Proceeding: 2017 AIChE Annual Meeting
- Group: Topical Conference: Nanomaterials for Applications in Energy and Biology
Tuesday, October 31, 2017 - 1:06pm-1:24pm
In line with this objective, exploiting theoretical first principles approaches, we have engineered anionic fluorine (F) doped transition metals non-oxide pnictide (TMN) based electro-catalyst for OER in PEM water electrolysis. The dopant-F plays a vital role in enhancing the electro-catalytic activity by altering the electronic structure of the electro-catalyst. The as-synthesized electro-catalyst with F content of 10 wt. % consequently exhibits excellent electro-catalytic performance, outperforming the benchmark IrO2 for OER in PEM water splitting. The as-synthesized electro-catalyst powder was coated on porous titanium (Ti) substrate (total catalyst loading=1 mg/cm2) and used as an anode. Electrochemical characterization of the electro-catalyst has been carried out in three-electrode configuration system, using 1N sulfuric acid (H2SO4) solution as the proton source as well as the electrolyte. Pt wire and Hg/Hg2SO4 are used as a counter electrode and reference electrode (+0.65 V with respect to the normal hydrogen electrode, NHE) respectively. Electrochemical evaluation has been conducted at a scan rate of 10 mV/sec and at temperature of 40oC. The generated PGM-free electro-catalyst exhibits an onset potential of ~1.43 vs NHE, similar to that of IrO2 but significantly lower charge transfer resistance (Rct) than benchmark IrO2. In addition, the as-synthesized electro-catalyst with F content of 10 wt. % displays a remarkable ~1.4 fold higher electro-catalytic OER activity (i.e. current density at 1.5 V) than that of IrO2 approaching a current density of ~ 10 mA/cm2 at an overpotential of ~ 245mV. Chronoamperometry tests conducted in 1N H2SO4 solution at ~1.5 V (vs NHE) for 24 hours also show marginal loss in current density, indicating good electrochemical stability of the as-prepared electro-catalyst. In summary, we have synthesized highly efficient PGM-free F doped TMN pnictide based electro-catalyst for OER in PEM based water electrolysis. The superior electrocatalytic activity of this electro-catalyst is attributed to the modification of the electronic structure (as evidenced by the theoretical studies) and lower charge transfer resistance (i.e. lower activation polarization). Thus, the present electro-catalyst system is indeed promising and beneficial for the economical and efficient hydrogen production from PEM water splitting. Results of these studies will be presented and discussed.
 A. S. Aricò, V. Baglio, N. Briguglio, G. Maggio, S. Siracusano, Fuel Cells: Data, Facts and Figures 2016.
 S. D. Ghadge, P. P. Patel, M. K. Datta, O. I. Velikokhatnyi, R. Kuruba, P. M. Shanthi, P. N. Kumta, RSC Advances 2017, 7, 17311-17324.
 S. A. Grigoriev, V. I. Porembsky, V. N. Fateev, International Journal of Hydrogen Energy 2006, 31, 171-175.