Given the seriousness of the energy problem and the lack of
stringent emission regulations, the search for a new type of clean
renewable energies has become the most important topic in the
energy sector. As an energy carrier, hydrogen is a promising means
of achieving clean combustion given that its major combustion
product is H2O when NOx emissions are well controlled [1]. Hydrogen
can generally be used in two ways: through direct combustion
and through hydrogen-fueled cells. However, hydrogen fuel cells
are limited by technical bottleneck and high price, such as proton
exchange membrane, carbon plate, and the high price of the metals
for catalysis. The direct combustion of hydrogen via hydrogenfueled
internal combustion engines (H2ICE) can easily and cheaply