钌基氧化物酸性析氧电催化剂
摘要
<p indent="0mm">The problems of energy scarcity, cost volatility and climate change are accelerating the move away from fossil fuels. Diversifying energy sources, investing in renewable energy sources, such as solar and wind power, can combat both the energy and climate crises. Hydrogen is a clean energy carrier that could be produced by water electrolysis. Electricity can be generated from off-grid power generators, such as solar and wind power. The oxygen evolution reaction (OER) is a key half reaction for hydrogen production by water electrolysis. The sluggish kinetics of the OER, caused by a complex multistep electron transfer process result in a high overpotential, inevitably limiting the energy conversion efficiency of water electrolysis. Thus, the development of highly active and stable OER electrocatalysts is an urgent task. Proton exchange membrane (PEM) electrolysis, a promising technology for green hydrogen production, has more advantages (e.g., higher current density, operating pressure, gas purity, and system compactness) compared to alkaline water electrolysis using an alkaline solution as electrolyte. However, the acidic operating environment imposes more stringent requirements on the stability of the catalyst. To date, the commercially available oxygen evolution reaction (OER) catalysts for PEM electrolysis are mainly iridium (Ir)-based materials. To achieve large-scale application of hydrogen production from water, relatively low-cost electrocatalysts are pursued to replace Ir in acidic media. In comparison with Ir-based materials, the ruthenium (Ru)-based oxide catalysts have the advantage of much lower cost but competitive OER activity. Thus, the Ru-based oxide catalysts are one of the most promising candidates for acidic OER in PEM water electrolysis. However, Ru-based oxide catalysts usually suffer from poor electrochemical stability in acidic media. The development of efficient and stable Ru-based oxide catalysts for acidic OER has received inc