It has been proved that 99% of total air emission is carbon dioxide. This is an actual problem and concern for earth future. Many ways to reduce CO2 emissions have been studied. One of the most important of them is using clean fuels. Hydrogen is widely accepted as a clean fuel that can be used without any harmful emissions. On the other hand, Hydrogen is an important middle product of petrochemical industries. There are some problems reducing the efficiency of Hydrogen production reactors. Relatively low conversion, high required temperature, cock formation and low amount of products are some problems in Hydrogen production systems. All of these problems will be reduced and eliminated by improving catalyst efficiency. Therefore, steam methane reforming (SMR), one of the best way to produce syngas, and its catalysts have been studied widely in recent years. In this paper, the latest achievements in catalysts and systems used in steam methane reforming have been reviewed.
