CoOx Particles Anchored on Pd/HAC Catalyst for Enhancing the Acetylene Dicarbonylation Performance
A series of CoOx-Pd/HAC catalysts were prepared by[Pd2(µ-CO)2Cl4]2 in situ formation of Pd nanoparticles by equivalent impregnation method,and their reactivity in acetylene dicarbonylation was investigated.It was found that the 3%Co-Pd/HAC catalyst has the best activity in the acetylene dicarbonylation(acetylene conversion 75.4%,dimethyl maleate selectivity 86.2%).The catalyst was characterized by X-ray diffraction(XRD),hydrogen temperature programmed reduction(H2-TPR)and transmission electron microscopy(TEM)and more.Moreover,the incorporation of an appropriate amount of metal cobalt oxide could drive electron migration on the surface of palladium nanoparticles,generate more high-valence Pd species,and increase the CO adsorption capacity,drive the dicarbonylation reaction step to Pdδ+↔Pd0 cycle process,so as to improve the acetylene dicarbonylation reaction activity.After seven cycles of experiments,the Co-Pd/HAC catalyst has a weak deactivation phenomenon,but has no significant effect on the selectivity of dimethyl butene-dicarboxylate.