Catalytic behaviour of Ni containing catalysts in vaporeforming of methane with low H_2O/CH_4 ratio and free carbon deposition

摘要

An active system for vaporeforming of methane with low H_2O/CH_4 ratio has been investigated starting from a LaNi_xFe_(1-x)O_3 perovskite (0<=x<=1) (96 percent CH_4 conversion, 96 percent CO selectivity) at 800degC. On most active systems (0.2<=x<=0.4), La(NiFe)O_3 structure, LaFeO_3 perovskite and well dispersed nickel particles are present after reaction without carbon deposition. Presence of nickel in the bulk and of the surface of the perovskite leads to strong interaction between small metal nickel particles and crystal lattice explaining the good ageing of this kind of catalysts.