Mikami Nagisa, Morishita Kei, Murakami Takeharu, Hosobata Takuya, Yamagata Yutaka, Ogawa Takayo, Mukouyama Yoshiharu, Nakanishi Shuji, Ager Joel W, Fujii Katsushi, Wada Satoshi
Advanced Photonics Technology Development Group, RIKEN Center for Advanced Photonics, 2-1 Wako, 351-0198 Saitama, Japan.
Ultrahigh Precision Optics Technology Team, RIKEN Center for Advanced Photonics, 2-1 Wako, 351-0198 Saitama, Japan.
ACS Energy Lett. 2024 Aug 1;9(9):4225-4232. doi: 10.1021/acsenergylett.4c01256. eCollection 2024 Sep 13.
Zero-gap-type reactors with gas diffusion electrodes (GDE) that facilitate the CO reduction reaction (CORR) are attractive due to their high current density and low applied voltage. These reactors, however, suffer from salt precipitation and anolyte flooding of the cathode, leading to a short lifetime. Here, using a zero-gap reactor with a transparent cathode end plate, we report periodic voltage oscillations under constant current operation. Increases in cell voltages occur at the same time as the reactor switches from the hydrogen evolution reaction (HER) to predominant CORR; decreases in cell voltage occur with the switch from the CORR to HER. Further, real time visual observations show that salt precipitation occurs during the CORR, whereas salt dissolution occurs during the HER. Slow flooding triggers the transition from the CORR to HER. A number of processes combine to slowly reduce the water content in the microporous layer, which triggers the transition back to the CORR.
具有气体扩散电极（GDE）且有助于一氧化碳还原反应（CORR）的零间隙型反应器，因其高电流密度和低施加电压而颇具吸引力。然而，这些反应器存在盐沉淀和阴极阳极电解液溢流问题，导致使用寿命较短。在此，我们使用具有透明阴极端板的零间隙反应器，报告了恒流操作下的周期性电压振荡。当反应器从析氢反应（HER）切换到主要的CORR时，电池电压会升高；当从CORR切换到HER时，电池电压会降低。此外，实时视觉观察表明，盐沉淀发生在CORR期间，而盐溶解发生在HER期间。缓慢的溢流触发了从CORR到HER的转变。许多过程共同作用，缓慢降低了微孔层中的含水量，从而触发了向CORR的转变。
