Gold supported yttrium oxide nanorods for catalytic oxidative cracking of n-propane to light olefins

An alkali assisted hydrothermal method was utilized to synthesize Y2O3 nanorods. Gold (0.5, 1.0, 1.5 and 2.0 wt %) supported Y2O3 nanorods samples were prepared by chemical reduction method and the synthesized Au-Y2O3 nanomaterials were utilized as catalysts for oxidative cracking of n-propane. The bulk Y2O3 nanorods showed n-propane conversion of 20% with 25% light olefins (ethylene and propylene) selectivity at 600 degrees C. Significant enhancement in both n-propane conversion and olefins selectivity were observed after gold deposition. Gold (1.5 wt%) supported Y2O3 nanorods (1.5Au-Y2O3-NR) sample offered highest activity (75.5% conversion of n-propane and 90.3% olefins selectivity) at 600 degrees C. The different techniques such as elemental analysis, powder X-ray diffraction, FT-IR, FE-SEM, DR UV-vis, N-2-physisorption, XPS and H-2-TPR measurements were used to determine physico-chemical properties of the synthesized catalysts. The characterization results revealed an existence of synergetic effect between the gold and Y2O3-NR support due to strong metal-support interaction. The superior catalytic activity of 1.5Au-Y2O3-NR sample is due to the fact that this catalyst possessed more number of mobile oxygen species, large number of Lewis acidic sites and also Au delta+-O-Y species. Time on stream analysis indicated that gold supported Y2O3 nanorod catalysts exhibited considerable stable activity for 24 h with slight loss of performance due to agglomeration of gold particles.