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Nano Research

Article Title

Catalytically active interfaces in titania nanorod-supported copper catalysts for CO oxidation

Keywords

supported catalysts, nanorod, oxygen species, interfacial active sites, CO oxidation

Abstract

One-dimensional titanium dioxide nanorod (TNR)-supported Cu catalysts (2.5 wt.%–12.5 wt.%) were synthesized using depositionprecipitation. X-ray photoelectron spectroscopy, temperature programmed reduction and CO chemisorption measurements showed that Cu doping over TNR offered metal-support interactions and interfacial active sites that had a profound impact on the catalytic performance. The role of the Cu-TNR interface was investigated by comparing the catalytic activity of Cu-TNR catalysts with that of pure CuO nanoparticles in CO oxidation. The presence of highly dispersed copper species, a high number of interfacial active sites, CO adsorption capacity and surface/lattice oxygen were found to be responsible for the excellent activity of 7.5Cu-TNR (i.e., Cu loading of 7.5 wt.% on TNR). Moreover, the Cu-TNR catalysts followed the Langmuir–Hinshelwood reaction mechanism with 7.5Cu-TNR, exhibiting an apparent activation energy of 44.7 kJ/mol. The TNR-supported Cu catalyst gave the highest interfacial catalytic activity in medium-temperature CO oxidation (120–240 °C) compared to other commonly used supports, including titanium dioxide nanoparticles (TiO2-P25), silica (SiO2) and alumina (Al2O3) in which copper species were nonhomogeneously dispersed. This study confirms that medium-temperature CO oxidation is highly sensitive to the morphology and structure of the supporting material.

Graphical Abstract

Publisher

Tsinghua University Press

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