Ni/TiO2 for low temperature steam reforming of methane

Abstract

Titanium dioxide-supported nickel (Ni/TiO2) catalyst was studied for the low temperature steam reforming of methane (SRM). While studies have frequently reported deactivation/inactivity of TiO2-supported metal catalysts under conventional high temperature methane reforming conditions, it is shown here that by applying activation treatments at a milder temperature of 400°C, Ni/TiO2 is able to maintain stable and effective hydrogen production at 500°C even at a low steam to methane input ratio of 1:1. Temperature programmed reduction studies showed that the presence of nickel species with stronger support interaction is crucial for the low temperature activation of methane while more weakly interacting nickel species contributed to hydrogen production via the water gas shift reaction. This observation was further confirmed when an identical reaction was performed with nickel supported on an inert oxide (silica) whereby the nickel species predominantly possessed a weaker metal–support interaction. When the amount of steam fed into the SRM system was increased, an enhancement in methane conversion by Ni/TiO2 was observed with up to 45% methane conversion achieved at 500°C for a H2O/CH4 feed ratio of 3. The Ni/TiO2 catalyst was shown to be capable of maintaining stable conversions and product selectivities for at least 96h, depending on the H2O/CH4 feed ratio.