Fuel cell research. Different catalysts used to produce hydrogen gas for fuel cells. In a fuel cell, hydrogen is combined with oxygen to produce water and electricity. One source of hydrogen is to produce it from hydrocarbons, such as methane gas, in what is called a steam-reforming reaction, followed by the water gas shift (WGS) reaction. The WGS reaction removes unwanted pollutants left after the steam-reforming stage, but requires catalysts unsuitable for commercial fuel cells. Finding a catalyst that can be used in commercial fuel cells will help fuel cell technologies become more widespread. Because fuel cells produce water vapour, they are less polluting than fossil fuels.