Zirconia Modified Ru/Al_2O_3 Catalysts for the Synthesis of Oxygenated Products From Syngas

摘要

Modification of Ru/Al_2O_3 by ZrO_2 has been carried out and tested in syngas conversion. Different coverages of ZrO_2 were attained by means of the controlled hydrolysis of a zirconium alkoxide on the Al_2O_3 surface. Characterization of the solids by XRD, TEM, TPR, FT-IR and XPS shows that a high dispersion of ZrO_2 over AL_2O_3 is attained. Impregnation of Ru on these solids gives rise to highly dispersed Ru particles preferentially associated to the ZrO_2 species. Under the reaction conditions ZrO_2/Al_2O_3 solids were almost inactive for syngas conversion. It was established that depending on pre-treatment and/or reaction conditions Ru could leave the surface as Ru carbonyls, the activity/selectivity patterns being dramatically dependent of the protocol followed.