Dimerization of Acetylene to Monovinylacetylene (MVA) by Bimetallic Zr/Cu Catalyst in Nieuwland Catalytic System

Nieuwland catalyst is a key step in the dimerization of acetylene. Various zirconium metal additives incorporating Nieuwland catalysts were prepared, and their catalytic performances were assessed in acetylene dimerization. Different characterization techniques (i.e., thermogravimetric analysis, temperature-programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, hydrogen ion concentration measurement and transmission electron microscopy) were employed in this study. The best catalytic performance was obtained over zirconium-acetylacetonate-incorporated Nieuwland catalysts, with an acetylene conversion of 53.3% and a monovinylacetylene selectivity of 87.4%. Based on these results, the zirconium acetylacetonate additive could reduce the types of transition state complexes, and it could also change the morphology of the catalyst. In addition, the additives could significantly inhibit the occurrence of trimerization products and polymers. Hence, the conversion of acetylene, monovinylacetylene selectivity, and stability of the Nieuwland catalysts were enhanced.

Automated summary

This study investigated the catalytic performance of Nieuwland catalysts incorporated with different additives in acetylene dimerization. The best catalytic performance was achieved with the zirconium-acetylacetonate-incorporated catalyst, which showed the highest acetylene conversion and monovinylacetylene selectivity. The zirconium acetylacetonate additive reduced the types of transition state complexes, changed the morphology of the catalyst, and inhibited the formation of trimerization products and polymers, thereby enhancing the conversion of acetylene and the stability of the Nieuwland catalysts.