The coadsorption of porphyrin molecules (TMPyP: tetra(N-methyl-4-pyridyl)-porphyrin), sulfate anions and copper on a Au(111) electrode was investigated by the use of cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy. With decreasing electrode potential the following sequence of surface phases was found: (I) an ordered � √ 3 × √ 7 � R19.1 • − SO 4 2− structure on the unreconstructed Au(111)-(1 × 1) surface; (II) a disordered SO 4 2−-layer on the still unreconstructed Au(111)-(1 × 1); (III) a � √ 3 × √ 3 � R30 • coadsorption structure of 2/3 ML Cu and 1/3 ML SO 4 2− ; (IV) a completed 1 ML Cu covered by a layer of mobile, i.e. not imaged, SO 4 2− anions, moreover, a coadsorption layer of disordered porphyrin molecules and still mobile SO 4 2− anions; (V) overpotentially deposited Cu-multilayers terminated by the well known Moiré-type modulated � √ 3 × √ 7 � R19.1 • − SO 4 2− structure (similar to bulk Cu(111)) and covered by a dense layer of flat lying TMPyP molecules showing a growing square as well as hexagonally ordered arrangement, and at even more negative potential values and low Cu concentrations in the solution (VI) a pseudomorphic underpotentially deposited Cu-monolayer covered by a � √ 3 × √ 7 � R19.1 • − SO 4 2− layer and a dense, ordered porphyrin layer ontop. The formation of the various phases is driven by the potential dependent surface charge density and the resultant electrostatic interaction with the respective ions. A severe imbalance between the copper deposition and desorption current in the CV spectra suggests also the formation of CuTMPyP-metalloporphyrin on the surface which diffuses into the bulk solution.
The methyl ester mixture obtained from rape oil, and the mixture of butyl esters produced from animal fatty acids, were converted into mixtures of ketones with a total yield above 65%. The experiments were performed at atmospheric pressure in a temperature range of 300±400°C using a standard¯ow system, with an iron catalyst modi®ed with silicon, chromium, and potassium oxides, in the molar ratio of 100:2:1:0.1. The described method may extend the prospects of using waste technical fats.
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