選択的および高電流のCO2は,ほぼ中性KCl電解質のマルチカーボン製品に電解
Xiao Zhang1, Jiachen Li1, Yuan-Yao Li1,2
1Department of Chemistry and BioX, Stanford University, Stanford, California 94305, United States.
Journal of the American Chemical Society
|February 22, 2021
まとめ
この研究は,二酸化炭素 (CO2) を価値あるマルチカーボン製品に減らすための安定した選択的電解剤を提示しています. ガス拡散層の電極上の新しい銅触媒は,ほぼ中性電解質で効率的に動作し,CO2削減の課題を克服します.
科学分野:
- 電気化学
- カタリシス
- 再生可能エネルギー
背景:
- 大気中のCO2の減少は,気候変動の緩和に不可欠です.
- 電気触媒によるCO2減量 (CO2RR) を多炭素 (C2+) 製品にするには,特に高電流密度では,選択性と安定性において課題があります.
- 既存のCO2RR方法では,アルカリ媒質での触媒分解が困難であることが多い.
研究 の 目的:
- CO2RRからC2+製品のための安定した選択的電気触媒を開発する.
- 銅の電気触媒の性能を,水害性ガス拡散層 (GDL) の電極で調査する.
- CO2RR性能をほぼ中性およびアルカリ性電解質で比較する.
主な方法:
- 銅の触媒を水害性の多孔ガス拡散層 (GDL) に置く.
- ほぼ中性KClとアルカリ的KOH電解質を用いて,H細胞とフロー細胞のセットアップでCu/GDL電極を試験する.
- 周期的なpH調整による2電極CO2電解器の構築と操作
主要な成果:
- Cu/GDL電極は,ほぼ中性であるKCl電解質で100 mA cm-2に近い高C2+部分電流密度を達成した.
- 安定したCO2RR性能がKClで観察され,KOHよりも優れていたが,Cuエッチング/腐食に起因するアルカリ媒体の触媒の不安定性があった.
- フローセル電解機は,安定したCO2RR活性と150 mA cm-2の選択性を30時間以上示し,C2+製品の75%のファラダイク効率と40%のエネルギー効率を達成した.
結論:
- シンプルな Cu/GDL 電極は,安定した選択的な CO2RR から C2+製品のための有望なプラットフォームを提供します.
- ほぼ中性電解質は,銅の腐食を抑制することによって,アルカリ媒介と比較して,触媒の安定性を大幅に高めます.
- 開発されたCO2電解器システムは,効率的な炭素捕集と利用技術の可能性を示している.
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