The IR Spectra of Mg5C2+(CO) Complexes on the (0 0 1) Surfaces of Polycrystalline and Single Crystal MgO | Sciact - CRIS-система Института катализа

The IR Spectra of Mg5C2+(CO) Complexes on the (0 0 1) Surfaces of Polycrystalline and Single Crystal MgO Научная публикация

Журнал

Surface Science
ISSN: 0039-6028

Вых. Данные

Год: 2003, Том: 540, Номер: 2-3, Страницы: L605-L610 Страниц : 1 DOI: 10.1016/S0039-6028(03)00830-6

Ключевые слова

Carbon monoxide, Infrared absorption spectroscopy, Low index single crystal surfaces, Magnesium oxides, Physical adsorption, Polycrystalline surfaces, Solid-gas interfaces, Vibrations of adsorbed molecules

Авторы

Spoto Giuseppe ^1,2 , Gribov Evgueni ^1,3 , Damin Alessandro ¹ , Ricchiardi Gabriele ^1,2 , Zecchina Adriano ^1,2

Организации

1	Dipartimento di Chimica IFM, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via P. Giuria 7, I-10125 Torino, Italy
2	INSTM UdR Torino Universita, Italy
3	Boreskov Institute of Catalysis, Novosibirsk, Russia

The FTIR spectroscopy of carbon monoxide adsorbed on polycrystalline MgO smoke has been investigated as a function of the CO equilibrium pressure at constant temperature (60 K) (optical isotherm) and of the temperature (in the 300–60 K range) at constant CO pressure (optical isobar). In both cases the spectra fully reproduce those of CO adsorbed on the (0 0 1) surface of UHV cleaved single crystals [Heidberg et al., Surf. Sci. 331–333 (1995) 1467]. This result, never attained in previous investigations on dispersed MgO, contribute to bridging the gap which is commonly supposed to exist between surface science and the study of “real” (defective) systems. Depending on the surface coverage θ the main spectral features due to the CO/MgO smoke interaction are a single band shifting from 2157.5 (at θ→0) to 2150.2 cm−1 (at θ=1/4) or a triplet, at 2151.5, 2137.2 and 2132.4 cm−1 (at θ>1/4). These manifestations are due to the ν(CO) modes of Mg5C2+· · · CO adducts formed on the (0 0 1) terminations of the cubic MgO smoke microcrystals. The formation of the CO monolayer is occurring in two different phases: (i) a first phase with CO oscillators perpendicularly oriented to the surface (2157–2150 cm−1) and (ii) a second phase constituted by an array of coexisting perpendicular and tilted species (triplet at 2151.5, 2137.2 and 2132.4 cm−1). A much weaker feature at 2167.5–2164 cm−1 is assigned to Mg4C2+· · · CO adducts at the edges of the microcrystals. The heat of adsorption of the perpendicular Mg5C2+· · · CO complex in the first phase has been estimated from the optical isobar and results to be 11 kJ mol−1.

Spoto G. , Gribov E. , Damin A. , Ricchiardi G. , Zecchina A.
The IR Spectra of Mg5C2+(CO) Complexes on the (0 0 1) Surfaces of Polycrystalline and Single Crystal MgO
Surface Science. 2003. V.540. N2-3. P.L605-L610. DOI: 10.1016/S0039-6028(03)00830-6 WOS Scopus РИНЦ CAPlusCA OpenAlex

Поступила в редакцию:	12 мар. 2003 г.
Принята к публикации:	29 мая 2003 г.
Опубликована online:	26 июн. 2003 г.
Опубликована в печати:	20 авг. 2003 г.

Web of science:	WOS:000184846500004
Scopus:	2-s2.0-0043162030
РИНЦ:	13443193
Chemical Abstracts:	2003:597988
Chemical Abstracts (print):	139:329650
OpenAlex:	W1969197577

БД	Цитирований
Web of science	33
Scopus	34
РИНЦ	32
OpenAlex	35