Abstract: This work explores the size-effect of zirconia nano particles on the catalysis of Au/ZrO₂-AN catalyst for 1,3-butadiene hydrogenation. Zirconia nanoparticles with different sizes(6—30 nm) were prepared by pretreatment at different temperatures(673—1 073 K) and 0.7%Au/ZrO₂-AN-T catalysts by deposition-precipitation method. The samples were characterized with XRD, TEM, XRF and nitrogen adsorption measurements. While the Au particles in all the 0.7%Au/ZrO₂-AN-T catalysts appeared to show similar sizes(4—5 nm), the catalytic activity order for 1,3-butadiene hydrogenation clearly revealed that smaller zirconia nanoparticles led to 1%Au/ZrO₂-AN-T catalyst with higher catalytic activities. A 100% selectivity to butenes is achieved and the trans to cis ratio in 2-butenes is 0.5—1 over all the 1%Au/ZrO₂-AN-T catalysts. The activity improvement by reducing zirconia particle size seems attributable to increased Au-zirconia junctions in the catalyst, as evidenced by the TEM analysis.

Key words: Au/ZrO₂ catalyst, 1,3-Butadiene hydrogenation, Zirconia nanoparticles, Size effect, Heterogeneous catalysis