Perovskite catalysts for hydrogen production from hydrogen sulfide

Abstract

Hydrogen production via catalytic thermal decomposition of hydrogen sulfide (H2S) was studied experimentally by synthesizing, characterizing and testing perovskite type catalysts; AxAʹ(1−x)ByBʹ(1−y)O3. In the formulation, A and Aʹ represented La and Sr respectively, B was chosen as Cr, and Bʹ was either Co or Mo or V. The subscript x of the perovskite structure was 0.9 and y values were 1, 0.75, 0.5 and 0.25.Catalytic thermal splitting of H2S was conducted in a continuous flow quartz reactor at atmospheric pressure and at temperatures ranging from 600 °C to 1000 °C using 150 ml/min H2S (1% vol.) total volumetric flow rate.The optimum Cr:Co ratio was found to be 0.33 at 950 °C where maximum equilibrium conversion of 36.3% was achieved with La0.9Sr0.1Cr0.25Co0.75O3. The perovskite involving Mo had a similar catalytic performance of 35.2%, at 950 °C. Direct thermal decomposition of hydrogen sulfide showed only 5.5% and 22.4% conversions at 900 °C and 950 °C respectively, which were far below the corresponding conversion values achieved with catalysts.