Synthesis of alkali promoted mesoporous, nanocrystalline Pd/TiO₂ catalyst for water gas shift reaction

Mesoporous, nanocrystalline alkali promoted Pd/TiO₂ (K-PT) catalyst was prepared by an evaporation induced self-assembly method using P123 as the pore generator. Series of catalysts were prepared by increasing the Pd molar ratio from 0.1 to 1.0. All of the prepared catalysts were characterized thoroughly by using different physico-chemical methods, such as X-ray diffraction, Raman, transmission electron microscopy, X-ray photoelectron spectroscopy, etc. Water gas shift (WGS) reaction was carried out in order to evaluate the catalytic activity of the prepared materials. Among all, the highest CO conversion has been observed with 0.8Pd/TiO₂. Introduction of K increases the CO conversion mainly at low temperature range between 200°C and 350°C. Interestingly, all the prepared catalysts show nearly 0% methane formation. In order to understand the relationship between structure and catalytic activity, the spent catalysts were also analyzed by all physico-chemical methods. Incorporation of K along with Pd reduces the extent of sintering, which in turn increases the stability of the catalyst during the course of WGS reaction.