کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
688376 | 1460124 | 2012 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Development of high-performance silver-based gas-diffusion electrodes for chlor-alkali electrolysis with oxygen depolarized cathodes Development of high-performance silver-based gas-diffusion electrodes for chlor-alkali electrolysis with oxygen depolarized cathodes](/preview/png/688376.png)
Silver-based gas-diffusion electrodes were prepared, characterized and tested during chlor-alkali electrolysis with oxygen depolarized cathodes. Spraying of aqueous suspensions containing silver catalyst particles, a PTFE suspension, a surfactant and an organic thickening agent on nickel nets followed by drying, hot-pressing and sintering allowed for the preparation of highly active electrodes. Electrodes obtained from the most suitable catalyst SF9ED (Ferro) were systematically investigated. The best electrodes contain 97–98 wt.% silver and 2–3 wt.% PTFE, are hot-pressed at ca. 130 °C with moderate pressure and subsequently sintered at temperatures around 340 °C. For these electrodes, half cell potentials of ca. 650 mV vs. RHE corresponding to electrolysis cell voltages of ca. 2.17 V at current densities of 4 kA/m2 were obtained. Both half cell and electrolysis cell voltages were found to be reproducible within about ±30 mV during repeated measurements using electrodes from different batches. While the Ag/PTFE loading had little influence on the observed voltages in the range studied (100–300 mg/cm2), loadings of at least 200 mg/cm2 are recommended to prevent leakage of NaOH electrolyte and to allow for operation under oxygen overpressures of more than 100 mbar without breakthrough of gas to the electrolyte.
► A method for reproducible preparation of ODCs for chlor-alkali electrolysis was developed.
► Measurements were performed in half cell and full electrolysis cell.
► Best electrodes showed 650 mV vs. RHE in half cell and 2.17 V in electrolysis cell at 4 kA/m2.
► Optimized Ag/PTFE loadings prevent oxygen and electrolyte breakthrough.
Journal: Chemical Engineering and Processing: Process Intensification - Volume 52, February 2012, Pages 125–131