Nondeactivating Nanosized Ionic Catalysts for Water−Gas Shift Reaction

Abstract

The water−gas shift reaction (WGS) is an important reaction to produce hydrogen. In this study, we have synthesized nanosized catalysts where Pt ion is substituted in the +2 state in TiO2, CeO2, and Ce1−xTixO2−δ. These catalysts have been characterized by X-ray diffraction and X-ray photoelectron spectroscopy (XPS), and it has been shown that Pt2+ in these reducible oxides result in solid solutions like Ti0.99Pt0.01O2−δ, Ce0.83Ti0.15Pt0.02O2−δ, and Ce0.98Pt0.02O2−δ. These catalysts were tested for the water gas shift reaction both in the presence and absence of hydrogen. It was shown that Ti0.99Pt0.01O2−δ exhibited higher catalytic activity than Ce0.83Ti0.15Pt0.02O2−δ and Ce0.98Pt0.02O2−δ. Further, experiments were conducted to determine the deactivation of these catalysts. There was no sintering of Pt and no carbonate formation; therefore, the catalyst did not deactivate even after prolonged reaction. There was no carbonate formation because of the highly acidic nature of Ti4+ ions in the catalysts.