Oxidation of 1,3-Butadiene over Nickel- and Copper-Based Catalysts: Exploring the Effectiveness of Ceria and Niobia Supports

Abstract

This study investigates the oxidation of 1,3-butadiene (BD), which is a classified hazardous air pollutant with a high degree of toxicity, over the temperature range of 300–650 °C. The intent in this work is to find an efficient method of destroying toxic, carcinogenic, and unstable BD, which can cause storage problems as well and, in the process, exploring the possibility of its conversion to useful industrial starting materials, such as synthesis gas. BD, being an unsaturated hydrocarbon, is reactive to oxidation with the right combination of heterogeneous catalysts. For this purpose, we investigate the role of Ni- and Cu-based catalysts with different loadings on alumina, niobia, and ceria–niobia combinations to track the yield and selectivity of the obtained products in the temperature range of 300–650 °C. The product selectivity and relative yields were obtained through gas chromatography (GC) combined with mass spectrometry and thermal conductivity detector, while Fourier transform infrared spectroscopy (FTIR) is also used to corroborate the GC results. The main objective of this work was to identify the best catalyst for BD oxidation in the low-mid temperature range. Furthermore, in order to investigate the degree of dispersion, morphology, metal–support interactions, surface areas, pore sizes, and redox capabilities of the catalysts and their potential influence on the oxidation reaction, comprehensive characterization methods such as X-ray diffraction, FTIR, scanning electron microscopy with energy-dispersive spectra, nitrogen adsorption and desorption, and hydrogen-temperature-programmed reduction were employed. It is seen that 10% copper loading CeO₂ and Nb₂O₅ showed optimal catalytic performance with 100% conversion of butadiene and the highest product selectivity at all temperatures. The findings of this study entail a practical environmental application of oxidation reactions in dealing with toxic compounds as constituents of hydrocarbon emissions from exhaust through efficient heterogeneous catalysis.