Adsorption and Desorption of HCI on Pt(111)

Journal Article · Tue Jul 26 04:00:00 EDT 2005 · Journal of Physical Chemistry B, 109(32):15506-15514

DOI:https://doi.org/10.1021/jp058139p· OSTI ID:15020030

Daschbach, John L; Kim, Jooho; Ayotte, Patrick; Smith, R Scott; Kay, Bruce D

The adsorption and desorption of HCl on Pt(111) is investigated by temperature programmed desorption (TPD), infrared reflection absorption spectroscopy (IRAS), and low energy electron diffraction (LEED). Five peaks are identified in the TPD spectra prior to the onset of multilayer desorption. For (theta > 0.38 ML, theta = 1.5x1015 cm-2) HCl adsorbs molecularly at 20 K as an amorphous solid with two desorption peaks at 70 and 77 K. A third peak at 84 K is tentatively assigned to molecularly adsorbed HCl. Peaks at ~135 and 200 K are assigned to recombinative desorption of dissociated HCl, in agreement with earlier studies. Kinetic analysis is conducted and the results demonstrate a strong coverage dependent desorption energy for theta < 0.25 ML. The LEED data indicates that at low temperature the adsorbed HCl clusters into ordered islands with a (3 x 3) structure and a local coverage of 4/9 with respect to the Pt(111) substrate.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15020030
• Report Number(s): PNNL-SA-44943; 6500; 2398; KC0301020
• Journal Information: Journal of Physical Chemistry B, 109(32):15506-15514, Journal Name: Journal of Physical Chemistry B, 109(32):15506-15514 Journal Issue: 32 Vol. 109; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
ADSORPTION
DESORPTION
ELECTRON DIFFRACTION
Environmental Molecular Sciences Laboratory
HYDROCHLORIC ACID
KINETICS
PLATINUM
SORPTIVE PROPERTIES