为了确定还原终点，通过UV-Vis监测还原过程，观察槭树叶提取物中有机

In order to determine the end point of reduction, the reduction process was monitored by UV-Vis, and the change of the characteristic absorption peak of organic matter in the maple leaf extract at 320 nm was observed. The results are shown in Figure 3. It is found from Figure 3 that with the extension of the reduction time, the organic matter is consumed by Pd2+ during the reduction process, and the absorption peak gradually decreases. The reduction of Pd2+ proceeds rapidly one hour before the start of the reaction, and the absorbance of the reducing substance is significantly reduced. After continuing to extend the reaction time to 4 h and continuing to delay the time, the peak of the reduction product no longer changes, indicating that the Na2PdCl4 precursor has been completely reduced.

In order to determine the reduction end point, the reduction process is monitored by UV-Vis to observe the change of the characteristic absorption peak of organic matter in the eucalyptus leaf extract at 320 nm, and the results are shown in Figure 3. It is found from Figure 3 that with the extension of the restoration time, organic matter is consumed by Pd2 plus during the restoration process, and the absorption peak is gradually reduced. The reduction of Pd2 plus reacts quickly one hour before the reaction begins, and the absorbentness of the reduced substance is significantly reduced. After the continuous extension of the reaction time to 4 h, the delay time continues and the peak of the reduced object does not change, indicating that the Na2PdCl4 precarns are fully restored.

In order to determine the reduction end point, the reduction process was monitored by UV Vis to observe the change of characteristic absorption peak of organic matter in maple leaf extract at 320 nm. The results are shown in Figure 3. It can be seen from Figure 3 that with the extension of reduction time, the organic matter is consumed by Pd2 + during the reduction process, and the absorption peak decreases gradually. The reduction of Pd2 + takes place rapidly one hour before the beginning of the reaction, and the absorbance of the reducing substance decreases obviously. When the reaction time was prolonged to 4 h, the peak of the reduced product did not change, indicating that the reduction of na2pdcl4 precursor was completed.<br>