铜锰型CO常温消除催化剂水汽中毒机制的研究

通过对一种典型的铜锰型催化剂--德国德尔格催化剂通水蒸气条件下失活规律的研究,以及XRD,XPS,TG-DTA,TEM等物理手段对催化剂失活前后结构特点的表征,我们发现,催化剂失活前后,其体相结构和微观形貌没有明显的改变,但失活催化剂表面上出现了明显的碳酸盐组分。作者认为,锰离子具有较多的d空轨道,在有水蒸气存在的条件下,可能成为水分子的强吸附中心。滞留于催化剂表面的水分子与CO2反应生成碳酸根,掩盖了活性位,导致催化剂失活。

Mechanism of Deactivation of Copper Manganese Oxide Catalysts for CO Oxidation in Humidity at Room Temperature

One of typical copper manganese oxide catalysts for CO oxidation was evaluated at room temperature in humidity. The characteristic of deactivation of the catalyst was investigated. Methods of XRD, XPS, TG-DTA, TEM were employed for investigation of the structure difference of deactivated catalysts from the counterpart before evaluated. The results show that the bulk phase and microcosmic structure of the catalysts have no evident change after being evaluated, however, marked carbonate species appear on the surface of the catalysts. It is deduced that in the presence of vapor, manganese ion could be the site for strong adsorption of water, as it has more empty d orbit. Water remained on the surface of catalyst can react with CO2, producing carbonate species. The active sites are covered by them, leading to the deactivation of catalysts.