셀레늄을 활용한 니켈철 (옥시)수산화물의 격자 산소 활성화 (Lattice Oxygen Activation in NiFe (Oxy)hydroxide using Se)

서지정보

· 발행기관 : 한국재료학회
· 수록지 정보 : 한국재료학회지 / 32권 / 8호 / 339 ~ 344페이지
· 저자명 : 조승환, 손정인

초록

The lattice oxygen mechanism (LOM) is considered one of the promising approaches to overcome the sluggish oxygen evolution reaction (OER), bypassing -OOH* coordination with a high energetic barrier. Activated lattice oxygen can participate in the OER as a reactant and enables O*-O* coupling for direct O2 formation. However, such reaction kinetics inevitably include the generation of oxygen vacancies, which leads to structural degradation, and eventually shortens the lifetime of catalysts. Here, we demonstrate that Se incorporation significantly enhances OER performance and the stability of NiFe (oxy)hydroxide (NiFe) which follows the LOM pathway. In Se introduced NiFe (NiFeSe), Se forms not only metal-Se bonding but also Se-oxygen bonding by replacing oxygen sites and metal sites, respectively. As a result, transition metals show reduced valence states while oxygen shows less reduced valence states (O-/O2 2-) which is a clear evidence of lattice oxygen activation.
By virtue of its electronic structure modulation, NiFeSe shows enhanced OER activity and long-term stability with robust active lattice oxygen compared to NiFe.

영어초록

The lattice oxygen mechanism (LOM) is considered one of the promising approaches to overcome the sluggish oxygen evolution reaction (OER), bypassing -OOH* coordination with a high energetic barrier. Activated lattice oxygen can participate in the OER as a reactant and enables O*-O* coupling for direct O2 formation. However, such reaction kinetics inevitably include the generation of oxygen vacancies, which leads to structural degradation, and eventually shortens the lifetime of catalysts. Here, we demonstrate that Se incorporation significantly enhances OER performance and the stability of NiFe (oxy)hydroxide (NiFe) which follows the LOM pathway. In Se introduced NiFe (NiFeSe), Se forms not only metal-Se bonding but also Se-oxygen bonding by replacing oxygen sites and metal sites, respectively. As a result, transition metals show reduced valence states while oxygen shows less reduced valence states (O-/O2 2-) which is a clear evidence of lattice oxygen activation.
By virtue of its electronic structure modulation, NiFeSe shows enhanced OER activity and long-term stability with robust active lattice oxygen compared to NiFe.

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