Robert Przekop

Texture of Al2O3-SnO2 binary oxides system obtained via sol–gel chemistry

Abstract A comprehensive comparative study of binary oxide systems obtained by the co-precipitation method and sol–gel chemistry has been made. Particular attention has been paid to the texture changes and crystallographic differences between the systems synthesized by the above two methods.

Pyrolytic and catalytic conversion of rape oil into aromatic and aliphatic fractions in a fixed bed reactor on Al2O3 and Al2O3/B2O3 catalysts

In the, at present, unstable fuel market, much attention is devoted to alternative technologies for fuel production and development of alternative products of the petrochemical industry. One of the prospective sources of fuel and alternative petrochemical products is biomass, and the use of oil plants is one of the possibilities. This paper reports on a possible conversion of rapeseed oil produced in Poland into intermediate hydrocarbon fractions by pyrolysis combined with parallel catalytic conversion. The products were analysed by gas chromatography coupled with a mass detector. The process was performed in a fixed-bed reactor and was monitored by FTIR and 1H NMR. Depending on the catalysts applied, the products contained: water, carbon oxides, hydrogen, aliphatic or aromatic hydrocarbons accompanied by some amount of C2-C5 hydrocarbons formed during the cracking process.

One-pot method of synthesis of Pt/SnO2 system and its electrocatalytic activity

BackgroundElectro-oxidation of methanol in acidic solution was investigated on a Pt/SnO2 based electrocatalyst obtained by the sol–gel method. Pt/SnO2 systems were prepared by one pot synthesis using a sol–gel method and tin (IV) acetate as a precursor of SnO2 and water solution of hexachloroplatinum acid as a source of metallic phase.ResultsThe described method, thanks to its simplicity and mildprocessing temperature, offers uniform dispersion of metal phase in the bulk of the gel forming as a result of hydrolysis and condnastionon of tin precursor. It has been found that the obtained system exhibits high electrocatalytic activity just after low temperature processing. This work investigates the effect of the Pt concentration and the influence thermal treatment of Pt/SnO2 on its electrochemical activity.ConclusionsThe described procedure is a simple method of producing a highly active Pt/SnO2 electrocatalyst without using thermal treatment in reducing conditions. The oxidation state of Pt is a determining factor for its activity in an electrooxidation process.Graphical AbstractOne-pot method of synthesis of Pt/SnO2 catalyst

Platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex as a pt source for Pt/SnO 2 catalyst

This paper presents new preparation method of Pt/SnO2, an important catalytic system. Besides of its application as a heterogenic industrial catalyst, it is also used as a catalyst in electrochemical processes, especially in fuel cells. Platinum is commonly used as an anode catalyst in low temperature fuel cells, fuelled with alcohols of low molecular weight such as methanol. Platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex was used as a precursor of metallic phase. The aim of the research was to obtain a highly active in electrochemical system Pt/SnO2 catalyst with low metal load. Considering small size of Pt crystallites, it should result in high activity of Pt/SnO2 system. The presented method of SnO2 synthesis allows for obtaining support consisting of nanoparticles. The effect of the thermal treatment on activity of Pt/SnO2 gel was demonstrated. The system properties were investigated using TEM, FTIR (ATR), and XRD techniques to describe its thermal structural evolution. The results showed two electrocatalytical activity peaks for drying at a temperature of 430 K and above 650 K.

Physicochemical and surface properties of alumina modified with rare earth oxides, III. Dispersion of supported platinum

The effect of various amounts of lanthanides on the dispersion of Pt on Al2O3 — Ln2O3 (where Ln = La, Ce) has been studied by hydrogen chemisorption in a pulse chromatographic system.

Alumina and silica preparation via a sol–gel route with carbon dioxide as a pH regulator – a new method for green catalysis

This paper presents a new preparation method of SiO2 and Al2O3via a sol–gel route with CO2 as a pH regulator. The influence of carbon dioxide as a pH moderator on the textural parameters is demonstrated. The properties of the oxide xerogels were investigated using SEM, TEM, FT-IR, thermal analysis techniques, and low temperature nitrogen adsorption measurements to describe their structural evolution. The results illustrate differences in the final textural properties of the systems obtained depending on the pH regulator used in the synthesis. The method proposed is doubly beneficial as it eliminates the use of (organic or inorganic) acids and represents an interesting and new application of carbon dioxide.