Effect of Re addition on the WGS activity and stability of Pt/CeO₂-TiO₂ catalyst for membrane reactor applications

The catalytic performance of RePt/CeO₂-TiO₂ catalysts for the WGS reaction under conditions compatible with membrane reactor was investigated. The WGS activity and stability of the Pt/CeO₂-TiO₂ catalyst was significantly influenced by the addition of rhenium. The intrinsic WGS activity per atom of platinum improves with the addition of Re to Pt/CeO₂-TiO₂ catalyst. The addition of rhenium also has a beneficial effect on its stability under WGS conditions compatible with membrane reactor use. The improvement in WGS activity and stability is proposed to be associated with the improvement in the reduction behavior of the highly dispersed CeO₂ and ReO _x species present in the bimetallic RePt catalyst respect to the monometallic Pt/CeTi counterpart and to the presence of rhenium species in close contact with Pt that could introduce an additional redox activity sites stable under WGS conditions and/or prevent the sintering of Pt crystallites under WGS conditions.