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Composition of Chemisorption Layers Forming on a Chromium Electrode in Sulfuric Acid Solutions of Formaldehyde and Formic, Oxalic, and Glyoxylic Acids

“…Sulfur was present in trace quantities. The thickness of layers containing chemisorption products at the chromium surface was estimated from the attenuation of the intensity of lines Cr 2 p [1]. It amounted to 2.0-2.2 nm for the conditions under which chromium was in contact with solutions of organic substances at open-circuit potentials and to 2.3-2.5 nm, in the case of interaction in conditions of imposition of cathodic polarization.…”

“…Values of ∆ E b (C-B j ) for the C1 s line [17] (R is the hydrocarbon radical; M is the metal ion; Y = OR, CH 3 ; m + n = 3) solvable into components. 1 The lines have peaks at 287.6 and 289.0 eV (Figs. 1a, 2a).…”

“…The electrocatalytic transformations, at the surface of chromium, of three organic substances-methyl alcohol, dimethylformamide (DMF) and oxalic acid (OA)-in contact with it in sulfuric acid solutions was discovered in [1]. Surface layers formed at compact polycrystalline chromium in said solutions under opencircuit conditions and during its cathodic polarization were investigated in [1] ex situ with the aid of a method of x-ray photoelectron spectroscopy (XPS).…”

“…Surface layers formed at compact polycrystalline chromium in said solutions under opencircuit conditions and during its cathodic polarization were investigated in [1] ex situ with the aid of a method of x-ray photoelectron spectroscopy (XPS). It was established that, under open-circuit conditions, organic substances undergo strong chemisorption and the composition of chemisorbed species differs from the composition of initial molecules.…”

“…For example, on metal samples that were in contact with a DMF solution, the line corresponding to the core electronic levels of nitrogen is absent in an XPS spectrum, which testifies to the cleavage of the C-N bond. Besides, an analysis of spectra for the C 1 s line, performed in [1], showed that reduced functional groups and hydrocarbon fragments, which to one degree or another interact in a coordination manner with chromium atoms, appear at the metal surface after contact with all the three compounds. Information of that kind was undoubtedly of interest for studying the mechanism of the formation of amorphous chromium coatings (deposits) out of Cr(III) electrolytes in the presence of simplest oxygen-containing organic compounds.…”