4,6-二氨基间苯二酚合成工艺中Pd/C催化剂失活原因分析

Study on the Deactivation of Pd/C Catalyst in the Synthesis of 4,6-Diamino-resorcinol

通过采用原子吸收、XRD、物理吸附、DSC-TGA等分析手段对在4,6-二氨基间苯二酚合成过程中发生失活的Pd/C催化剂的活性组分、比表面积、孔容及孔径的变化、热失重和晶相结构进行分析,以及对失活催化剂进行再生处理,对催化剂的失活原因进行了研究。结果表明:催化剂在反应过程中发生了积炭失活,通过用碱溶液或有机溶剂进行洗涤可以部分去除催化剂表面沉积的有机物,使催化剂的表面得以改善;在后处理过程中催化剂中的金属钯由于与HCl反应生成PdCl2造成金属钯的大量流失是使催化剂发生失活的主要原因。

The causes for the deactivation of Pd/C during the course of synthesizing 4,6 - diamino - resorcinol were investigated. The active component content, BET surface area, pore volurae, pore average diameter, thermogravimetry and crystal structure of the deactivated catalysts were analyzed by the methods of atomic absorption, physisorption, DSC - TGA and X - ray diffraction. The results showed that carbonaceous deposits happened during the course of hydrogenation and which could be partly cleaned up by washing the catalysts with basic solution or organic solvent; in the post - treatment, nearly half of the metal Pd dissolved in the solution by reacting with HCl and the leaching of Pd was the main cause for the deactivation of Pd/C catalysts.