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  • Author or Editor: W. Jóźwiak x
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Abstract  

This study presented results on reduction of alumina supported chromium and platinum–chromium catalysts using temperature programmed reduction method (TPR). It has been shown that catalysts after earlier oxidation step but without calcinations one undergo reduction in lower temperature in comparison to calcined only catalysts. Moreover, addition platinum to Cr/Al2O3 catalysts also caused decrease of reduction temperature. It has been observed that over the examined catalysts oxidation CO to CO2 and reduction CO to CH4 occurs. However, on Pt–Cr catalysts both reactions proceed at lower temperature compare to Cr catalysts.

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Abstract  

Alumina supported Mo and Pt-Mo catalysts was subject to temperature programmed reduction (TPR) using H2 and CO. After earlier oxidation step TPR–H2 profiles shows different surface species, which depends on the composition of the catalysts and reduction temperature. Change in reducing gas from H2 into CO results in significant changes in catalyst system. Hydrogen causes a decrease in oxidation number of metals, while carbon monoxide reacts with chemisorbed chemicals.

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Summary

The effect of conditioning the silica layer by mobile phase vapour or ammonia vapour on the retention of alkaloids eluted with non-aqueous mobile phases was examined. The effect of vapour phase composition on system efficiency, peak symmetry, and separation selectivity were also investigated. The most effective and selective systems were used for separation of the alkaloid fraction of Datura innoxia.

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Abstract  

Thermal decomposition of compounds consisting of tetrahalogenocuprate(II), [CuBrnCl4−n]2− (n=0–4) anions and a tetraethylammonium cation has been studied using TG-FTIR, TG-MS, DTA and DTG techniques. The measurements were carried out in an argon and air atmospheres over the temperature range 293-1073 K. The products of the thermal decomposition were identified by IR and Far Infrared (FIR) spectroscopy as well as X-ray powder diffractometry.

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