Powder and structured Pt/Ce0.75Zr0.25O2-based catalysts: Water gas shift performance and quasi in situ XPS studies.

The data on the performance in water gas shift reaction of a powder 5 wt% Pt/Ce 0.75 Zr 0.25 O 2 and a structured 0.33 wt% Pt/Ce 0.75 Zr 0.25 O 2 /θ-Al 2 O 3 /FeCrAl catalysts are reported in this work. For the powder one the lowest outlet CO concentrations were shown to be 0.5, 0.9 and 1.5 vol% corresponding to the initial ones of 5, 10 and 15 vol%, respectively; the temperature required to reach these values did not exceed 310 °C. The quasi in situ XPS data have shown that doping CeO 2 with Zr enhances the reducibility of the oxide allowing Ce3+ formation without any treatment. Additionally, it was found that there are 20–30% of nonmetallic Pt atoms on the surface even after a treatment in CO at 300 °C. For the structured catalyst the downward temperature gradient along the monolith was observed with a dispersion of 50–60 °C. The lowest CO concentrations were observed at the temperatures at the catalyst's back point of 280 °C–3.9 and 4.3 vol% CO in the dry gas for 15,700 and 31,400 cm3·g cat −1·h−1, respectively, for 10 vol% CO in the feed gas. • The powder and structured catalysts 5 wt% Pt/Ce 0.75 Zr 0.25 O 2 for water gas shift reaction. • The catalysts show a good performance below 350 °C in reformate-simulating mixtures. • Doping CeO 2 with Zr allows Ce3+ on the oxide surface without any treatment. • 20–30% of surface Pt atoms are in nonmetallic state even in a reductive atmosphere. [ABSTRACT FROM AUTHOR]