Abstract
Pt-nanoparticles with tuneable size between 0.8nm and 8nm supported on nanocrystalline CeO2 was prepared by surfactant promoted hydrothermal synthesis method and their activity was studied for low temperature water-gas-shift (WGS) reaction. The catalyst was characterized by XRD, ICP-AES, N2-sorption, H2-pulse chemisorption, TPR, XPS, SEM, TEM, and EXAFS. The average Pt particle size, measured by HR-TEM were 0.8nm, 3.7nm and 7. 8nm when the Pt loading on CeO2 was 0.9wt%, 1.9wt% and 4.7wt%. The catalyst with 0.9wt% Pt loading supported on CeO2 (0.9Pt-CeO2) showed the best catalytic activity of 85.1% CO conversion with CO2 formation rate of 1.66×1010molcm−1s−1. The activity of the catalysts decreased with increasing Pt size and Pt loading on CeO2. The influence of reaction parameters like time-on-stream, temperature, gas hourly space velocity (GHSV), etc. were also studied in detail. The XPS study revealed that the fresh catalyst contained Pt2+, which is the active species for water-gas-shift reaction. The catalyst (0.9Pt-CeO2) did not change any activity till 30h in time-on-steam at 140°C showing the stability of the Pt-nanoparticles at 140°C. When the size of the Pt was increased above 1nm the WGS activity decreased with time as the Pt2+ reduced to metallic Pt at 140°C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
