Preparation of Nano Pd/C Catalyst for Purification of Terephthalic Acid by Sol-Gel Method

The traditional method of preparing 0.5 wt.% nano Pd/C catalysts used for pure terephthalic acid(PTA) refining is the precipitate-reduction method, and this paper proposed the sol-gel method, in which the palladium colloid was firstly prepared, and followed by the load process onto the activated carbon. The activity and microstructure of catalysts were investigated by means of SEM, TEM, EDS，XRD and HPLC. It was found that the activity of catalyst with the sol-gel method was much higher than that with precipitate-reduction method. The preparation technology has less effects on the micostructure of Pd/C catalysts, while the palladium particles of catalyst obtained with sol-gel method are much finer and the relatively palladium content is much higher.These two factors contribute to the higher activity of Pd/C catalyst.