Effect of Support Geometry on Catalytic Activity of Pt/CeO₂Nanorods in Water Gas Shift Reaction

Abstract

>> Nanorod and particle shape CeO2 were synthesized via hydrothermal process and precipitation method, respectively, and used as supports of Pt catalyst for water gas shift (WGS) reaction. Three different durations (12, 48, and 96h) for hydrothermal process were applied for the preparation of nanorod type CeO2. 1.0 wt% of Pt was loaded on the prepared supports with incipient wetness method prior to the catalytic activity tests that were carried out at a GHSV of 95,541 h -1, and a temperature range of 200 to 360 o C. Varying duration of hydrothermal process led to the difference in physical characteristics of CeO2 nanorods, such as aspect ratio, BET surface area, pore diameter, and pore volume. Consequently, the catalytic activities of Pt/CeO2 nanorods were affected by the physical characteristics of the supports and appeared to be in the order of Pt/CeO2(12) > Pt/CeO2(48) > Pt/CeO2(96). The comparison of the catalytic activities and results of the analysis (XPS, XRD, SEM, BET and TPR) for the supports revealed that the activity of the catalysts depends on chemical states of the Pt and the support materials in the temperature range that is lower than 280 o C. However, the activity is rather dependent on the physical characteristic of the supports because the increased gas velocity limits the mass transfer of reactants in micropores of the supports.

Platinum Based Catalysts in the Water Gas Shift Reaction: Recent Advances

“…Im et al [29] compared nanorod and particle shape CeO 2 as a support of platinum-based catalysts. The supports were synthesized through hydrothermal process (for nanorod support) and through precipitation method (for particle shape support).…”