DIMCO · Development and Investigation of Manganese-doped NiFe nanosheet Catalyst for Oxygen Evolution Reaction

Development and Investigation of Manganese-doped NiFe nanosheet Catalyst for Oxygen Evolution Reaction

Fossil fuels (e.g., coal, gasoline and natural gas etc.) serve as the dominant energy source for electricity generation, heating, transportation and so on, as they are cheap and abundant, accounting for approximately 80% of the world energy supply. However, the use of this carbon source is finite and leads to emissions including a lot of toxic air pollutants and carbon dioxide (CO2) which has been established as one of the most critical driving forces of climate change. Negative impacts of the climate change have been already visible, including increase of sea level, ocean acidification as well as harm to human health. Until we get out of the fossil fuel dependence, such terrible consequences will be continued and grow as a significant threat to our future generations. Hydrogen (H2) has been paid much attention as an alternative energy source to the fossil fuels. H2 is directly used as a fuel for Fuel Cell systems to generate electricity and moreover it is used as a precursor for making useful chemicals such as alcohols, ammonia and various organic compounds. Although currently steam methane reforming accounts for the majority of hydrogen production, generating inevitably CO2, H2 can be also produced from water (H2O), avoiding any harmful emissions, which is what’s called electrochemical water splitting. During the water electrolysis, hydrogen evolution reaction (HER) at cathode and oxygen evolution reaction (OER) at anode take place at the same time and the overall system efficiency is highly dependent of the capability of anode catalyst to promote OER due to its slow reaction rate compared with the HER. Precious noble-metal-based materials such as ruthenium oxide (RuO2) and iridium oxide (IrO2) have exhibited high catalytic activity and stability for the OER at a wide range of pHs. Nonetheless, they are fairly rare and costly for a large scale application and hence considerable efforts have been dedicated to developing cheap and active catalysts that are made of earth-abundant materials such as nickel (Ni), cobalt (Co) and iron (Fe). NiFe-based (oxy)hydroxide among their combinations is widely studied and well known as a benchmark catalyst. In order to further improve the performance and guide rational design of NiFe oxides catalysts, this project aims to study fundamental questions of which metal is more responsible for the OER activity between Ni and Fe by using diverse analysis techniques. As a result, it is proved that Ni and NiFe catalyze the OER in different ways and Fe-dependent structural change plays an important role in the OER activity. Moreover, a possible way of using FeOOH in the form of nanocluster on the surface of NiOOH is suggested to achieve improvement of the OER performance over the benchmark NiFe oxides.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз