Study On The Property Of Catalyst For Reductive Desulfurization With Oxygen

The damage of sulfur dioxide to human being and the environment is getting worse and worse. So to accelerate the step of FGD is gradually important and urgent. The problem is that the O2 in flue gas tends to have a negative effect on the catalytic reduction reaction. It can reduce the activity of catalysts which are high activity in no oxygen condition, even make them deactivated. So it is significant to find out how oxygen affects catalysts and discorver high active catalyst.The dissertation explored the pre-sulfurized process of LaCoO3, analysed the phase transformation, and studied catalytic activity and structural changes with oxygen.Substitution of strontium in LaCoO₃ was also researched and investigated the effect of Co state on catalytic performance.The results of experiments are that the decomposition temperature of LaCoO₃ was 550℃, when the LaCoO3 was sulfurized to the compound La₂O₂S, CoS₂, La₂(SO₄)₃ and La₂O₃, they had high activity. CoS₂ was easily sulfurized to CoO with oxygen, and correspondingly catalytic activity decreased. The phase structure of La₂O₂S was comparatively steady indeed, but its catalytic performance and lifetime were not good. The substitution of strontium has important influence on existent state of cobalt, and cobalt disulfide has to do with the catalyst lifetime intimately.