Assessment of the intricate nickel-based anodic reactions mechanism within a methanol fed solid oxide fuel cell based on a co-ionic conducting composite electrolyte
Abstract
We propose here a comprehensive modelling approach to predict the intricate anodic electrochemical reactions within a direct methanol fed solid oxide fuel cell based on a H+/O2- dual conducting composite electrolyte. We assess the effect of the ionic transference number (tn) on open circuit voltage of the cell operating at 650 °C, 700 °C and 750 °C to determine an optimum tn. The modelling proposes three electrochemical reactions scenarios associated to direct methanol fed solid oxide fuel cell i.e. (1) full methanol oxidation (2) total methanol reforming and subsequent light gases oxidations (3) mixed oxidation of unconverted methanol and light gases. Simulation results prove the capability of scenario 2 to predict adequately the anodic reactions mechanism indicating the total reforming of methanol over the Nickel-samarium doped ceria anode at 650 °C and the electrochemical oxidation of around 1% and 7% of methanol molecules at 700 °C and 750 °C, respectively. Furthermore, scenario 1 exhibits the highest efficiency ∼50% in the temperature range between 650 °C and 750 °C with limited fuel utilization ∼39%. Nevertheless, the fuel utilization increases to 30% and 70% at 650 °C and 750 °C respectively, when using scenario 3.
- Publication:
-
Journal of Power Sources
- Pub Date:
- February 2019
- DOI:
- 10.1016/j.jpowsour.2018.12.071
- Bibcode:
- 2019JPS...414..115M
- Keywords:
-
- Solid oxide fuel cell;
- Dual conduction;
- Modelling;
- Methanol reforming;
- Methanol electrochemical oxidation;
- Transference coefficient