Anion Exchange Membrane Fuel Cells with Improved CO2-Tolerance: Impact of Chemically Induced Bicarbonate Ion Consumption
Anion Exchange Membrane Fuel Cells with Improved CO2-Tolerance: Impact of Chemically Induced Bicarbonate Ion Consumption
复制标题
具有改进的 CO2 耐受性的阴离子交换膜燃料电池：化学诱导碳酸氢根离子消耗的影响
DOI：
10.1021/acsami.7b09877
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发表时间：
2017
影响因子：
9.5
通讯作者：
and Koichi Eguchi
中科院分区：
文献类型：
--
作者：
Yu Katayama;Kosuke Yamauchi;Kohei Hayashi;Takeou Okanishi;Hiroki Muroyama;Toshiaki Matsui;Yuki Kikkawa;Takayuki Negishi;Shin Watanabe;Takenori Isomura;and Koichi Eguchi
在过去的几十年里，由于阴离子交换膜的重大发展，越来越多的人致力于实现阴离子交换膜燃料电池（aemfc），该电池使用现场产生的氢气供应。本文以氨为氢源，考察了杂质、未反应nh3和大气CO2对aemfc性能的影响。正如预期的那样，我们发现这些杂质显著地恶化了aemfc的性能。此外，借助原位衰减全反射红外（ATR-IR）光谱，揭示了电池性能的下降主要是由于抑制了氢氧化反应（HOR）。这是由于来自（bi）碳酸盐类的co相关类占据了活性位点。有趣的是，在NH3和hco3的存在下，由于NH3的存在诱导了碳酸氢盐离子消耗反应，HOR活性的这种降解受到抑制。进一步的原位ATR-IR和电化学分析表明，在nh3 - hco3条件下，有毒的co相关物质被完全去除，并伴有HOR活性的提高。最后，利用实际的AEMFC进行了燃料电池试验，阳极为含nh3的H2gas，阴极为环境空气。结果证实了nh3 - hco3共存对aemfc的co2耐受性有积极影响的有效性。在燃料中没有任何杂质的情况下，电池性能达到了近95%。这些结果清楚地表明，化学诱导的碳酸氢盐离子消耗反应对实现高耐co2的aemfc的影响。
Over the last few decades, because of the significant development of anion exchange membranes, increasing efforts have been devoted the realization of anion exchange membrane fuel cells (AEMFCs) that operate with the supply of hydrogen generated on-site. In this paper, ammonia was selected as a hydrogen source, following which the effect of conceivable impurities, unreacted NH3and atmospheric CO2, on the performance of AEMFCs was established. As expected, we show that these impurities worsen the performance of AEMFCs significantly. Furthermore, with the help of in situ attenuated total reflection infrared (ATR-IR) spectroscopy, it was revealed that the degradation of the cell performance was primarily due to the inhibition of the hydrogen oxidation reaction (HOR). This is attributed to the active site occupation by CO-related adspecies derived from (bi)carbonate adspecies. Interestingly, this degradation in the HOR activity is suppressed in the presence of both NH3and HCO3–because of the bicarbonate ion consumption reaction induced by the existence of NH3. Further analysis using in situ ATR-IR and electrochemical methods revealed that the poisonous CO-related adspecies were completely removed under NH3–HCO3–conditions, accompanied by the improvement in HOR activity. Finally, a fuel cell test was conducted by using the practical AEMFC with the supply of NH3-contained H2gas to the anode and ambient air to the cathode. The result confirmed the validity of this positive effect of NH3–HCO3–coexistence on CO2-tolerence of AEMFCs. The cell performance achieved nearly 95% of that without any impurity in the fuels. These results clearly show the impact of the chemically induced bicarbonate ion consumption reaction on the realization of highly CO2-tolerent AEMFCs.