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 Ce_1-xTi_xO_2-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 Ti_0.99Pt_0.01O_2-δ, Ce_0.83Ti_0.15Pt_0.02O_2-δ, and Ce_0.98Pt_0.02O_2-δ. These catalysts were tested for the water gas shift reaction both in the presence and absence of hydrogen. It was shown that Ti_0.99Pt_0.01O_2-δ exhibited higher catalytic activity than Ce_0.83Ti_0.15Pt_0.02O_2-δ and Ce_0.98Pt_0.02O_2-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.