Role of surface hydroxyl groups in promoting room temperature CO sensing by Pd-modified nanocrystalline SnO{sub 2}

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.07.017· OSTI ID:21421484

Marikutsa, Artem V., E-mail: [e-mail] ^[1]; Rumyantseva, Marina N., E-mail: [e-mail].r ^[1]; Yashina, Lada V., E-mail: [e-mail].r ^[1]; Gaskov, Alexander M., E-mail: [e-mail].r ^[1]

---

1. Chemistry Department, Moscow State University, Moscow 119991 (Russian Federation)

SnO{sub 2}/Pd nanocomposites were synthesized via sol-gel method followed by variable processing procedures. The materials are sensitive to CO gas in the concentration range 2-100 ppm at room operating temperature. It was shown that modification of nanocrystalline tin dioxide by Pd changes the temperature dependence of sensor response, decreasing the temperature of maximal signal. To understand the mechanism of room temperature CO sensitivity, a number of SnO{sub 2}/Pd materials were characterized by XRD, TEM, BET, XPS and TPR techniques. From the results of FTIR, impedance and sensing measurements under variable ambient conditions it was concluded that improvement in CO sensitivity for Pd-modified SnO{sub 2} is due to alteration of CO oxidation pathway. The reaction of CO with surface OH-groups at room temperature was proposed, the latter being more reactive than oxygen species due to the possible chain character of the reactions. It was proposed that Pd additive may initiate chain processes at room temperature. - Graphical abstract: Nanocrystalline SnO{sub 2} modified by PdO/Pd clusters exhibit high CO sensitivity at room temperature. An extensive study revealed surface OH-groups participation in CO oxidation on SnO{sub 2} leading to enhanced sensitivity at low operating temperature (25-150 {sup o}C). PdO/Pd clusters supposedly initiate a chain of CO reactions with surface hydroxyls.

• OSTI ID: 21421484
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 10; Other Information: DOI: 10.1016/j.jssc.2010.07.017; PII: S0022-4596(10)00299-9; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
CARBON MONOXIDE
COMPOSITE MATERIALS
CRYSTALS
HYDROXIDES
INFRARED SPECTRA
NANOSTRUCTURES
PALLADIUM
PALLADIUM OXIDES
SENSITIVITY
SENSORS
SOL-GEL PROCESS
SURFACES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TIN OXIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROGEN COMPOUNDS
MATERIALS
METALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PALLADIUM COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PLATINUM METALS
SCATTERING
SPECTRA
SPECTROSCOPY
TEMPERATURE RANGE
TIN COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS