Ni/SiO2催化剂上甲烷催化裂解制氢

The catalytic decomposition of methane as an alternative process for the production of hydrogen from natural gas has been studied. The results show that a 15% Ni/SiO2 catalyst has good activity for decomposition of methane to hydrogen and carbon deposit. The capacity of methane decomposition is 4.5 g CH4/g catalyst at reaction temperature range of 550 ℃～600 ℃. It means that the Ni/SiO2 catalyst is still active during deposition of several thousands carbon atoms on a Ni0 atom. It can be reasonably explained by the mechanism of carbon filament formation. The catalytic activity can be fully regenerated by either air oxidation or steam gasification and the catalyst is stable after 10 successive decomposition/regeneration cycles. XRD analyses indicate that no apparent increase in the amount of carbon remaining on the catalyst after successive regenerations and no structural changes in the nickel particles.