Optimization of sample preparation of mono- and bimetallic catalysts based on Sibunit carbon carrier for quantitative analysis by ICP-AES

Abstract

Composite materials like «Sibunit» are used as carriers for heterogeneous catalysts. These materials exhibit high mechanical strength, chemical purity, high resistance to aggressive environment, and controlled porous structure. The components of such catalysts are noble metals, and their combinations with oxides of some transition metals. An urgent task in their production is to control the content of the active component in the composition of catalysts. This characteristic affects the phase and electronic state of the metal, the structural and textural characteristics of the carbon carrier, and hence determines the activity and selectivity of catalysts during operation. Quantitative chemical analysis thus becomes one of the main methods for controlling the quality of catalysts. Different options for acid decomposition of mono- (Pd/C, Ru/C, Ga/C) and bimetallic (Pd-Ga/C, Pd-Zn/C, Pd-Ru/C, Pd-Ag/C) catalytic systems based on carbon carrier «Sibunit» are considered. The goal of this study is determination of the content of metals by inductively coupled plasma atomic emission spectrometry. The effect of the main operating parameters of the spectrometer on the intensity of sensitive and non-overlapping spectral lines of the elements being determined was studied. Optimal conditions for measuring the analytical signal were chosen. It is shown that for the studied bimetallic systems, with the exception of Pd-Ru/C, it is possible to choose a sample preparation option that allows simultaneous quantitative determination of two components from one sample. The developed method of quantitative analysis is characterized by rather high accuracy. The relative error of the element determination does not exceed 3 %, the relative standard deviation is not more than 5 %. The results of the study can be used to analyze catalysts of similar chemical composition by inductively coupled plasma atomic emission spectrometry.