The new generation of fuel cells is less sensitive against carbon monoxide and many new catalysts synthesized in the past years have better long term stability and selectivity. However, CO is produced either as a product or by-product and therefore there is need to remove or separate otherwise the performance of the fuel cells will be significantly affected. In the steam reforming process, methanol is converted to hydrogen and carbon dioxide. During this process it depends on the reaction path way at the used catalyst in which explicit intermediates are favored. The main reaction is the Steam Reforming of Methanol (SRM). The Methanol Decomposition (MD) is a parallel reaction which appears negligible at good catalysts.
Many strategies have been invented to lower the amount of carbon dioxide given out in the reformate gases or to purify the hydrogen from the CO gas. For instance, a WGS reactor can be subsequently attached to the reformer or preferential CO oxidation (PROX) can reduce the carbon monoxide content. A study of Ozkara-Aydinoglu et al reported the advantages of a Pt/CeO2 catalyst which has oxygen storage capacity (OSC) and showed an excellent activity at lower temperatures.
Catalysis of Fossil Fuel Production
The major catalytic processes for energy conversion have been developed for petroleum, natural gas, and coal (Table 1). Other processes include power-plant emissions, and conversion of hydrogen in fuel cells. Fractional distillation has been in use in petroleum refineries to yield transportation fuels and petrochemicals. Catalytic conversions of the various fractions are then employed in processing a number of goals; removal of sulfur, nitrogen, and metals from the oil molecules. In addition, reaction of small molecules to give larger molecules, restructuring molecules to improve quality as well as cracking of large molecules to give smaller ones. These processes involve hydrogen gas as reactant, for example, in hydrodesulfurization, hydrodenitrogenation, and hydrodemetallization, which respectively produce H2S, NH3, and solid metal sulfides.
