Influence of the Crystal Structure of Titanium Oxide on the Catalytic Activity of Rh/TiO in Steam Reforming of Propane at Low Temperature.

Solid oxide fuel cells (SOFCs) with liquefied petroleum gas (LPG) reduce CO emissions due to their high-energy-conversion efficiency. Although SOFCs can convert LPG directly, coking occurs easily by decomposition of hydrocarbons, including C-C bonds on the electrode of fuel cell stacks. It is therefore necessary to develop an active steam pre-reforming catalyst that eliminates the hydrocarbons at low temperature, in which waste heat of SOFCs is used. Herein, we show that the crystal structure of the TiO that anchors Rh particles is crucial for catalytic activity of Rh/TiO catalysts for propane pre-reforming. Our experimental results revealed that strong metal support interaction (SMSI) induced during H pre-reduction were optimized over Rh/TiO with a rutile structure; this catalyst catalyzed the reaction much more effectively than conventional Rh/γ-Al O . In contrast, the SMSI was too strong for Rh/TiO with an anatase structure, and the surface of the Rh particles was therefore covered mostly with partially reduced TiO . The result was very low activity.