Phosphoric acid fuel cells (PAFC) are a type of that uses liquid as an. They were the first fuel cells to be commercialized. Developed in the mid-1960s and field-tested since the 1970s, they have improved significantly in stability, performance, and cost. Such characteristics have made the PAFC a good candidate for early stationary ap.
Phosphoric acid fuel cells (PAFC) are a type of fuel cell that uses liquid phosphoric acid as an electrolyte. They were the first fuel cells to be commercialized. Developed in the mid-1960s and field-tested since the 1970s, they have improved significantly in stability, performance, and cost.
Can phosphoric acid be discharged from a fuel cell?
This implies that phosphoric acid in the electrolyte layer cannot be easily discharged from the fuel cell together with the cell exhaust gas, although even such minute discharge, results in the degradation of cell performance in the long term. A conceptual working principle is described in Figure 1.
Is phosphoric acid an electrolyte in fuel cells?
Phosphoric acid as an electrolyte in fuel cells was discovered in 1961 by Elmer Rey and Tanier and became the electrolyte of choice for fuel cells for power plant power generation in the 70s of the 20th century. Phosphoric acid has many advantages as an electrolyte:
At lower temperatures phosphoric acid is a poor ionic conductor, and CO poisoning of the platinum electro-catalyst in the anode becomes severe. However, they are much less sensitive to CO than proton-exchange membrane fuel cells (PEMFC) and alkaline fuel cells (AFC).
PAFC uses phosphoric acid as an electrolyte and generally uses hydrogen as fuel. Hydrogen enters the gas chamber, and after reaching the anode, it loses 2 electrons under the action of the anode catalyst and oxidizes to H +. Anodic reaction: $$ {text {H}}_ {2} to 2 {text {H}}^ {+} + 2 {text {e}}^ {-}$$
Electrolyte is highly concentrated or pure liquid phosphoric acid (H 3 PO 4) saturated in a silicon carbide (SiC) matrix. Operating range is about 150 to 210 °C. The electrodes are made of carbon paper coated with a finely dispersed platinum catalyst. Anode reaction: 2H 2 (g) → 4H + + 4e Cathode reaction: O 2 (g) + 4H + + 4e‾ → 2H 2 O