title: Designing CuOx Nanoparticle-Decorated CeO2 Nanocubes for Catalytic Soot Oxidation: Role of the Nanointerface in the Catalytic Performance of Heterostructured Nanomaterials.
abstract: This work investigates the structure-activity properties of CuOx-decorated CeO2 nanocubes with a meticulous scrutiny on the role of the CuOx/CeO2 nanointerface in the catalytic oxidation of diesel soot, a critical environmental problem all over the world. For this, a systematic characterization of the materials has been undertaken using transmission electron microscopy (TEM), transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDS), high-angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM), scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS), X-ray diffraction (XRD), Raman, N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS) techniques. The TEM images show the formation of nanosized CeO2 cubes (∼25 nm) and CuOx nanoparticles (∼8.5 nm). The TEM-EDS elemental mapping images reveal the uniform decoration of CuOx nanoparticles on CeO2 nanocubes. The XPS and Raman studies show that the decoration of CuOx on CeO2 nanocubes leads to improved structural defects, such as higher concentrations of Ce(3+) ions and abundant oxygen vacancies. It was found that CuOx-decorated CeO2 nanocubes efficiently catalyze soot oxidation at a much lower temperature (T50 = 646 K, temperature at which 50% soot conversion is achieved) compared to that of pristine CeO2 nanocubes (T50 = 725 K) under tight contact conditions. Similarly, a huge 91 K difference in the T50 values of CuOx/CeO2 (T50 = 744 K) and pristine CeO2 (T50 = 835 K) was found in the loose-contact soot oxidation studies. The superior catalytic performance of CuOx-decorated CeO2 nanocubes is mainly attributed to the improved redox efficiency of CeO2 at the nanointerface sites of CuOx-CeO2, as evidenced by Ce M5,4 EELS analysis, supported by XRD, Raman, and XPS studies, a clear proof for the role of nanointerfaces in the performance of heterostructured nanocatalysts.
authors.affiliation: Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Applied Sciences, RMIT University , Melbourne, Victoria 3001, Australia.
authors.forename: Putla
authors.initials: P
authors.lastname: Sudarsanam
authors.affiliation: Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Applied Sciences, RMIT University , Melbourne, Victoria 3001, Australia.
authors.forename: Brendan
authors.initials: B
authors.lastname: Hillary
authors.affiliation: Inorganic and Physical Chemistry Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology , Uppal Road, Hyderabad, Telangana 500 007, India.
authors.forename: Baithy
authors.initials: B
authors.lastname: Mallesham
authors.affiliation: Inorganic and Physical Chemistry Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology , Uppal Road, Hyderabad, Telangana 500 007, India.
authors.forename: Bolla Govinda
authors.initials: BG
authors.lastname: Rao
authors.affiliation: Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Applied Sciences, RMIT University , Melbourne, Victoria 3001, Australia.
authors.forename: Mohamad Hassan
authors.initials: MH
authors.lastname: Amin
authors.affiliation: Chemistry Department, College of Science, King Saud University , Riyadh 12372, Saudi Arabia.|Chemistry Department, Faculty of Science, Sohag University , Sohag 11432, Egypt.
authors.forename: Ayman
authors.initials: A
authors.lastname: Nafady
authors.affiliation: Chemistry Department, College of Science, King Saud University , Riyadh 12372, Saudi Arabia.
authors.forename: Ali M
authors.initials: AM
authors.lastname: Alsalme
authors.affiliation: Inorganic and Physical Chemistry Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Technology , Uppal Road, Hyderabad, Telangana 500 007, India.
authors.forename: B Mahipal
authors.initials: BM
authors.lastname: Reddy
authors.affiliation: Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Applied Sciences, RMIT University , Melbourne, Victoria 3001, Australia.
authors.forename: Suresh K
authors.initials: SK
authors.lastname: Bhargava