Pt/ZrO_2 catalyst for a single-stage water-gas shift reaction: Ti addition effect

摘要

Ti modified Pt/ZrO_2 catalysts were prepared to improve the catalytic activity of Pt/ZrO_2 catalyst for a single-stage WGS reaction and the Ti addition effect on ZrO_2 was discussed based on its characterization and WGS reaction test. Ti impregnation into ZrO_2 increased the surface area of the support and the Pt dispersion. The reducibility of the catalyst was enhanced in the controlled Ti impregnation (~20 wt.%) over Pt/ZrO_2 by the Pt-catalysed reduction of supports, particularly, at the interface between ZrO_2 and TiO_2. The significant CO_2 gas band in the DRIFTS results of Pt/Ti[20]/ZrO_2 indicated that the Ti addition made the formate decomposition rate faster than the Pt/ZrO_2 catalyst, linked with the enhanced Pt dispersion and reducibility of the catalyst. Consequently, Ti impregnation over the ZrO_2 support led to a remarkably enhanced CO conversion and the reaction rate of Pt/Ti[20]/ZrO_2 increased by a factor of about 3 from the bare Pt/ZrO_2 catalyst.