Spatial confinement:An effective strategy to improve H_(2)O and SO_(2) resistance of the expandable graphite-modified TiO_(2)-supported Pt nanocatalysts for CO oxidation  

作　　者：Hongtai Zhu Wenge Qiu RuiWu Kai Li Hong He 

机构地区：[1]Key Laboratory of Beijing on Regional Air Pollution Control,Beijing Key Laboratory for Green Catalysis and Separation,Beijing University of Technology,Beijing 100124,China [2]Advanced E-Catal.Corporation,Ltd.,Beijing 100025,China

出　　处：《Journal of Environmental Sciences》2025年第2期57-68,共12页环境科学学报(英文版)

基　　金：supported by the National Key R&D Program of China (No.2017YFC0210303).

摘　　要：The expandable graphite(EG)modified TiO_(2) nanocomposites were prepared by the high shearmethod using the TiO_(2) nanoparticles(NPs)and EG as precursors,in which the amount of EG doped in TiO_(2) was 10 wt.%.Followed by the impregnation method,adjusting the pH of the solution to 10,and using the electrostatic adsorption to achieve spatial confinement,the Pt elementswere mainly distributed on the exposed TiO_(2),thus generating the Pt/10EG-TiO_(2)-10 catalyst.The best CO oxidation activity with the excellent resistance to H_(2)O and SO_(2) was obtained over the Pt/10EG-TiO_(2)-10 catalyst:CO conversion after 36 hr of the reaction was ca.85%under the harsh condition of 10 vol.%H_(2)O and 100 ppm SO_(2) at a high gaseous hourly space velocity(GHSV)of 400,000 hr−1.Physicochemical properties of the catalystswere characterized by various techniques.The results showed that the electrostatic adsorption,which riveted the Pt elements mainly on the exposed TiO_(2) of the support surface,reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs,hence significantly improving CO oxidation activity over the Pt/10EG-TiO_(2)-10 catalyst.The 10 wt.%EG doped in TiO_(2) caused the TiO_(2) support to form a more hydrophobic surface,which reduced the adsorption of H_(2)O and SO_(2) on the catalyst,greatly inhibited deposition of the TiOSO_(4) and formation of the PtSO4 species as well as suppressed the oxidation of SO_(2),thus resulting in an improvement in the resistance to H_(2)O and SO_(2) of the Pt/10EG-TiO_(2)-10 catalyst.

关 键 词：Expandable graphite Electrostatic adsorption Titania supported platinum CO oxidation Resistance to H_(2)O and SO_(2) 

分 类 号：X703[环境科学与工程—环境工程]