Metal-organic frameworks (MOFs) are widely used in various fields because they make it easy to control porous structures according to combinations of metal ions and organic linkers. In addition, ZIF (zeolitic imidazolate framework), a type of MOF, is made up of transition metal ions such as Co2+ or Zn2+ and linkers such as imidazole or imidazole derivatives. ZIF- 67, composed of Co2+ and 2-methyl imidazole, exhibits both chemical stability and catalytic activity. Recently, due to increasing need for energy technology and carbon-neutral policies, catalysis applications have attracted tremendous research attention. Moreover, demand is increasing for material development in the electrocatalytic water splitting and metal-air battery fields; there is also a need for bifunctional catalysts capable of both oxidation/reduction reactions. This review summarizes recent progress of bifunctional catalysts for electrocatalytic water splitting and metal-air batteries using ZIF-67. In particular, the field is classified into areas of thermal decomposition, introduction of heterogeneous elements, and complex formation with carbonbased materials or polyacrylonitrile. This review also focuses on synthetic methods and performance evaluation.

Abstract
1. 서 론
2. ZIF-67을 이용한 수전해 이기능성 촉매
    2.1. ZIF-67 열분해
    2.2. ZIF-67 이종 원소 도입
    2.3. ZIF-67과 CNT 복합체 형성
3. ZIF-67을 이용한 금속-공기 전지 이기능성촉매
    3.1. ZIF-67과 금속산화물의 결합
    3.2. ZIF-67과 그래핀 복합체 형성
    3.3. ZIF-67과 polyacrylonitrile 복합체 형성
4. 결 론
References

• 김상준(부산대학교 재료공학과, 부산대학교 소재기술연구소) | Sang Jun Kim (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea, Institute of Materials Technology, Pusan National University, Busan 46241, Republic of Korea)
• 조승근(부산대학교 재료공학과) | Seung Geun Jo (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 박길령(부산대학교 재료공학과) | Gil-Ryeong Park (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 이은빈(부산대학교 재료공학과) | Eun Been Lee (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 이재민(부산대학교 재료공학과) | Jae Min Lee (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 이정우(부산대학교 재료공학과) | Jung Woo Lee (Department of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea) Corresponding author