時間解像度ラマンスペクトロシーによる銅電極における低超電位CO2-to-CO活性化のダイナミクスの探査
Jim de Ruiter1, Hongyu An1, Longfei Wu1
1Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
Journal of the American Chemical Society
|August 11, 2022
まとめ
時間解像度のスペクトロスコーピーは,CO2RRの間に酸化銅電極の再構成を明らかにします. パルス式電解は,ダイナミックな表面変化によって低ポテンシャルでCO2をCOに活性化し,効率的な一酸化炭素生産の洞察を提供します.
科学分野:
- 電気化学
- 材料科学
- 表面化学
背景:
- 酸化銅の電極は 有価な化学物質のCO2RRを高めます
- CO2RR中の電極の再構成を理解することは重要ですが,不完全です.
- ダイナミック・リストラクチャリングと電極性能の相互作用は明らかにする必要がある.
研究 の 目的:
- CO2RR中の銅 (酸化物) 電極のダイナミックな再構成を調査する.
- 時間解像度の高い表面強化ラーマン光譜法 (TR-SERS) を用いて反応中間物質の吸収を研究する.
- 電気化学データをスペクトル特性と相関させ,機械的な洞察を得ること.
主な方法:
- 時間解像度面強化ラーマン光譜法 (TR-SERS) を利用した.
- 電気化学的制御のためにサイクル電圧計 (CV) とパルス電解 (PE) を採用した.
- 電化学データとTR-SERSのスペクトル解析を組み合わせた.
主要な成果:
- 低超電位 (-0.35 V_RHE) で,10%のファラダイク効率で,PE中に観測されたCO2からCOへの活性化.
- ストカスティックなCO中介物質は,PEにおけるカソッドバイアスの発生直後に優勢である.
- 長期にわたる低過剰ポテンシャルで抑制されたCO中間物質;より高いバイアス (-0.55 V_RHE) で形成された静的なCO中間物質.
結論:
- 低過剰ポテンシャルCO2からCOの活性化は,Cu ((111)) 面曝露,部分的に酸化した表面,および銅炭酸水酸化物中間物質に起因する.
- ダイナミック・リストラクチャリングと表面介質は,CO2RRの活動と選択性に大きく影響します.
- 電気化学と組み合わせたTR-SERSは,CO2RRメカニズムを効果的に解明します.
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