EELS identification of the adsorbed species from acetone adsorption on Pt(111)

摘要: Adsorption of acetone on a clean Pt(111) surface at 120 K has been studied by high-resolution EELS and TDS. Two forms associatively adsorbed have characterized their structures determined. The more weakly bound, majority form, desorbs reversibly 185 (†Ha≈11.6 kcal mole−1) spectrum this species showed carbonyl stretching band (A1 symmetry) red shifted 80 cm−1 together with the two B1 skeletal modes viz. vas (CC) δ(CO), indicating bonding in an end on, through oxygen, η1(O) configuration, Pt-O-C bent most probably molecular plane. This form is the02 analog labile inorganic complexes which are widely exploited synthesis reactions. second more, strongly minority acetone, 210–230 K, partly desorbed molecularly while remainder decomposed to COa, Ha hydrocarbon residue stoichiometry C2Hx. no bands due but instead only methyl stretching, deformation rocking modes, side-on configuration designated η2(O,C). Its concentration was variable, depending region crystal probed beam consequently associated accidental, low-coordination, step sites. By inference, well defined close packed regions ideal surface.