Electrocatalysts Based on Metal Oxides for Hydrogen Evolution Reaction

In recent years, as energy security, environmental crisis and global warming have received increasing attention, the establishment of a fossil-fuel-free and renewable energy system is one of the most critical challenges facing mankind today. As a zero-carbon emission energy, hydrogen has been recognized as one of the cleanest sources, how to produce and consume hydrogen effectively and sustainably is the key for mankind to enter the hydrogen energy economy in the future, hydrogen production from water-splitting is recognized as the most efficient, promising and environmentally friendly hydrogen production method. The electrolysis water technology is based on the principle of electrochemical water splitting, using renewable electricity or solar energy to drive water-splitting into hydrogen and oxygen gas is considered to be the most sustainable way to produce hydrogen. However, the production of hydrogen by water splitting requires both active and stable cathode and anode catalysts to ensure the economy and energy saving of the entire water electrolysis reaction. At present, precious metal-based materials (such as Pt, Ru, Ir, etc.) are considered to be the most active electrocatalysts for the electrolysis of aquatic hydrogen, but their high cost and low reserves limit their large-scale application. Therefore, it is of great significance to explore highly efficient catalysts without precious metals for the industrial application of hydrogen electrolysis in aquatic products. In this chapter, the application research of metal oxides with different morphologies in the hydrogen evolution reaction in recent years is introduced in detail.