负载型Wacker催化剂的预处理及Pd和Cu含量的测定

用两种不同的方法对负载型Wacker催化剂进行预处理,并用ICP-AES法测定Pd和Cu的含量.实验表明,用烧灰-酸溶法预处理效果最好,方法中Pd和Cu的检出限分别为3.127和2.548ng·mL-1,加标回收率分别为96.26%和94.82%,11次测定的RSD(n=11)分别小于1.237%和1.354%.方法操作方便,分析速度快,结果准确.利用该法测定Wacker催化剂焙烧前、焙烧后和反应后Pd和Cu的含量,并与计算值比较,百分比分别大于96.4%和96.6%,可以认为,催化剂制备和反应过程中,活性组分没有流失.

Pretreatment of Supported Wacker Catalysts and the Determination of Palladium and Copper

The supported Wacker catalysts were pretreated with two different methods. Then copper and palladium were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The results showed that the best pretreatment method is burning-acid dissolving. With this method, the detection limits of Pd and Cu were 3.127 and 2.548 ng x mL(-1), the recoveries of standard addition of Pd and Cu were 96.26% and 94.82%, and the relative standard deviations (n=11) of Pd and Cu were less than 1.237% and 1.354%, respectively. The method is efficient, accurate, and easy to operate. Pd and Cu in supported Wacker catalysts, which were sampled before calcination, after calcination and after reaction, were determined by this method, and the contents were compared with calculated values. The percentages were larger than 96.4% and 96.6% respectively. It is considered that the active components did not decrease in preparation and reaction.