• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.151-151
• /
• 2016

수소는 친환경 에너지원으로 주목 받고 있으며 미래 화석연료의 고갈에 대비할 수 있는 물질이다. 수전해는 natural gas steam reforming 또는 coal gasification 같은 방법에 비해 공해 물질의 방출이 없어 미래지향적인 기술로 간주된다. 저온형 수전해는 크게 알칼리 수전해와 고분자 전해질막 수전해로 구분되며 각각의 기술은 장단점을 가지고 있다. 알칼리 수전해는 비백금계 물질을 촉매로 사용할 수 있는 이점이 있으나 알칼리 용액으로 인한 부식, 높은 과전압에 의한 효율저하 그리고 간헐적인 사용에 적합하지 않다. 고분자 전해질막 수전해는 간헐적인 사용이 용이하고 높은 에너지 밀도를 가지지만 산성분위기로 인한 백금계 촉매를 사용해야 하므로 수소 생산 비용이 증가하게 된다. 본 연구에서는 알칼리 수전해와 고분자 전해질막 수전해 방식의 이점을 최대한 이용하고 단점을 극복하기 위한 방법으로 음이온 교환막(anion exchange membrane, AEM)을 적용한 셀 구조를 소개한다. 본문에서는 AEM 수전해 단위 셀의 구성요소들인 AEM 종류, 가스 확산층의 밀도와 운전조건인 알칼리 수용액 농도, 온도의 조건을 다르게 하여 최상의 구성 요소 조건 및 운전조건을 알아보았다.

• Membrane Journal
• /
• v.31 no.2
• /
• pp.133-144
• /
• 2021

Alkaline water electrolysis system is the oldest technology among various hydrogen production processes to produce green hydrogen with the least amount of greenhouse gas generated. Alkaline water electrolysis (AWE) system is used in alkaline atmosphere condition. In comparison to polymer electrolyte membrane water electrolysis (PEMWE), this system can utilize stable transition metals such as nickel, cobalt, and silver, as electrode catalysts. AWE is relatively inexpensive, and can easily be scaled up to large scale. The system is a mature technology, as it has been in operation since the beginning of the 20th century in MW-scale for hydrogen generation, and there are currently more than 20 commercial manufacturers. In this review, the basic principles of AWE, along with catalysts, electrodes, and diaphragm membranes, are summarized. Particularly, the research and development trends of the diaphragm membrane unit, which is the core component of an AWE, are discussed in detail.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.46-46
• /
• 2014

알칼리 수전해는 신재생에너지를 이용하여 오염물질 없이 효율적으로 수소를 생산할 수 있는 방법 중의 하나이다. 알칼리 수전해 시스템의 산화전극으로 불용성전극이 많이 사용되고 있으나 높은 과전압과 제조 공정이 복잡한 문제점을 가지고 있다. 본 연구에서는 전기변색을 이용해 짙은 파란색의 $TiO_2$ 나노튜브를 알칼리 수전해 시스템의 산화전극으로 이용하고자 하였다. 양극산화법을 이용해 $TiO_2$ 나노튜브를 만드는 과정에서 양극산화 시간과 인가전압에 따라 Blue $TiO_2$의 산소발생반응(Oxygen evolution reaction, OER) 활성 변화를 측정하였고 나노튜브 길이가 길고 직경이 클수록 OER활성과 내구성이 향상되는 것을 확인하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.168.1-168.1
• /
• 2017

화석연료를 대체하기 위한 에너지원으로서 수소에너지에 대한 연구가 활발히 진행되고 있다. 수전해는 무한 청정한 물을 전기분해하여 수소를 생산하는 기술로써 대표적으로 알칼리 수전해(alkaline water electrolysis, AWE)와 고분자 전해질막 수전해(polymer electrolyte membrane water electrolysis, PEMWE)가 있다. 그 중, AWE는 알칼리 분위기에서 물분해 반응이 진행되어 촉매의 부식 위험성이 비교적 낮기 때문에 상대적으로 저렴한 비귀금속 산화물 촉매를 사용할 수 있다는 장점이 있다. 본 연구에서는 비귀금속인 Cu, Co를 이용하여 $CuCoO_4$를 합성한 후 산소 발생 촉매 물질로 활용하여 산소 발생 반응(Oxygen Evolution Reaction, OER)특성을 고찰하였다.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.4
• /
• pp.330-336
• /
• 2022

In order to evaluate the possibility as a separator in alkaline water electrolysis, the high temperature characteristics were evaluated by measuring the membrane resistance and durability of 5 types of commercial anion exchange membranes in 7 M KOH solution and at 80℃. The membrane resistance of AEM membrane measured in 7 M KOH solution and at 80℃ had a lower value of about 8-24 times compared to the other membranes. The durability of AEM membrane tested with the soaking time in 7 M KOH solution and at 80℃ showed a very good stability and that of FAAM40 and FAAM75-PK showed secondly a good stability. The thermal stability with the soaking time in 7 M KOH solution and at 80℃ of FAAM40 and FAAM75-PK membrane analyzed by thermo-gravimetric analysis showed a good stability compared to the other membranes.

• Transactions of the Korean hydrogen and new energy society
• /
• v.34 no.6
• /
• pp.575-580
• /
• 2023

An electrode was prepared by dip-coating NiFe₂O₄ powder on stainless steel (SUS) support for the application in the alkaline water electrolysis. The prepared electrode was analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), and was evaluated for the voltage properties with the change of current density in oxygen evolution reaction (OER) and hydrgen evolution reaction (HER) using 1, 3 and 7 M KOH solution. From the SEM and EDXS analysis, it was confirmed that the prepared electrode had NiFe₂O₄ on the SUS support. In OER and HER, the voltage in the 7 M KOH solution had a value of 1.35 and -1.90 V at 0.2 and -0.2 A/cm² of the current density, respectively. It was considered that the prepared electrode could be use as an electrode in the alkaline water electrolysis from the experimental results.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2002.05a
• /
• pp.143-148
• /
• 2002

SPE(solid polymer electrolyte) 수전해법은 고체고분자전해질 막(membrane)을 전해질로 사용하는 방법으로서 이 전해질 막은 알칼리 수전해에서의 KOH전해질과 격리막을 합쳐놓은 것과 같은 역할을 수행한다. SPE 수전해는 양극(anode)에서 촉매 전극에 의해 물로부터 산소기체(O$_2$)와 수소이온(H$^{+}$)이 발생되며 수소이온(H$^{+}$)은 다량의 물($H_2O$)분자와 함께 고체고분자전해질 막을 통하여 음극으로 이동하여 외부회로를 통해 도달한 전자(e)와 음극(cathode)에서 만나 수소기체(H$_2$)를 발생시키는 방법이다.(중략)

• Membrane Journal
• /
• v.27 no.6
• /
• pp.477-486
• /
• 2017

Hydrogen is one of energy storage systems, which could be transfer from electric energy to chemical energy or from chemical energy to electric energy, and is as an energy carrier. Water electrolysis is being investigating as one of the hydrogen production methods. Recently, water electrolysis receive attention for the element technology in PTG (power to gas) and PTL (power to liquid) system. In this paper, it was explained the principle and type for the water electrolysis, and recent research review for the alkaline water electrolysis.

• Journal of Energy Engineering
• /
• v.24 no.2
• /
• pp.34-39
• /
• 2015

This study confirmed the characteristics of hydrogen production according to electrode materials by producing non-diaphragm alkaline water electroanalyzer that can be controlled at medium temperature to produce hydrogen. As a result of the electrochemical characteristics by electrode material ($IrO_2/Ti$, $RuO_2/Ti$, Ti), the highest efficiency was found in $RuO_2/Ti$, as a result of hydrogen production experiment by electrolyte concentration, electrolyte concentration has a tendency to be proportional to hydrogen production and the condition of 30% KOH showed the highest hydrogen production as $118.9m^3/m^3/day$. In the experiment that confirmed hydrogen production according to electrode materials, in case of combination of anode ($IrO^2/Ti$) and cathode ($RuO^2/Ti$), it was $157.55m^3/m^3/day$ that showed a higher hydrogen production by around 6.97% than that of $IrO^2/Ti$ and cathode. It is presumed that the improvement of electrochemical activation of DSA electrode increases hydrogen production and influences the improvement of durability compared to the former electrode so that it enables stable alkaline water electrolysis.

• Transactions of the Korean hydrogen and new energy society
• /
• v.22 no.2
• /
• pp.184-190
• /
• 2011

The membrane properties (membrane resistance and ion exchange capacity) of the five types of commercial anion exchange membrane, i.e. IOMAC, AHT, APS, AHA, AFN, were evaluated for the application in the alkaline electrolysis. The membrane resistance decreased in the order; in 1M KOH: AHT>IOMAC>AHA>AFN>APS; in 1M NaOH: AHT>IOMAC>AHA>APS>AFN. The ion exchange capacity decreased in the order: AFN>APS>AHT>AHA>IOMAC. The membrane life was determined from the change of membrane resistance in 1M KOH and NaOH with an increase of soaking time in 20 wt% KOH and 30 wt% NaOH solution. AHA membrane had a good membrane life in 20 wt% NaOH with its unchanged membrane resistance. And, AFN and AHA membrane had a good membrane life in 30 wt% NaOH with its unchanged membrane resistance.