Hydrogen (H2) is widely concerned as the most potential candidate due to its high energy density and environmentally friendly reaction process. Electrochemical water splitting is a promising hydrogen production technology because it does not contain greenhouse gases and is economical and efficient. As a key semi-reaction process, the hydrogen evolution reaction (HER) plays a decisive role in the efficiency and cost of hydrogen production through electrochemical water splitting.

The reduction of fossil fuel sources, environmental pollution caused by engine fuel combustion, and concerns about energy supply have prompted researchers to look for renewable energy sources. Biodiesel has a high flash point (>130 °C), octane number and high combustion yield, as well as appropriate density and viscosity, excellent lubricants, and free sulfur and aromatic compounds. These characteristics have been applied to this engine without any modification and warm-up.

The nitrogen oxides (NOx) produced by mobile and stationary sources are the main sources of photochemistry and smog acid rain. Ammonia selective catalytic reduction (SCR) is one of the most effective methods for removing NOx. It is widely used in power plants and other industrial environments.Due to its high oxygen storage capacity and excellent redox characteristics of conversion between Ce4+ and Ce3+, the application of cerium oxide-based oxides in the NH3-SCR reaction has attracted more and more attention. However, compared with vanadium catalysts, the SO2 tolerance is a great challenge for CeO2 SCR catalysts applied in stationary sources especially at low and mediate temperatures.

Nitrogen oxides (NOx) emitted by fossil fuel combustion are one of the main air pollutants, posing a serious threat to the ecological environment and human health. To cope with huge environmental pressure and strict emission targets, NH3 selective catalytic reduction of NOx (NH3-SCR) is still the mainstream NOx control technology.