Ni- and Zn-promotion of γ-Al 2O 3 for the hydrolysis of COS under mild conditions

Abstract

The hydrolysis of COS using γ-Al 2O 3 as catalyst at 30°C is described. The effect of additives (ca. 3% Na, Fe, Co, Ni, Cu, Zn) is described in detail. The additives reduce the surface area of the γ-Al 2O 3 markedly but have no effect on the powder X-ray diffraction pattern. All significantly enhance the initial intrinsic activity (mol COS hydrolysed/m 2/h) when compared with unpromoted γ-Al 2O 3. However, this initial performance rapidly decays for the Na-, Fe-, Co- and Cu-modified catalysts. During this initial reaction period, of up to 5 h, the catalyst retains sulphur. In terms of specific activity (mol COS hydrolysed/g/h) only Ni- and Zn-promoted catalysts give a significant increase that is stable throughout the time-scale of these experiments.