观察图4(b)载体与催化剂的红外谱图可以发现在负载PdNPs后，在16

Observing the infrared spectrum of the support and catalyst in Figure 4(b), it can be found that after loading PdNPs, a new characteristic absorption peak appears at 1651 cm-1. This is due to the formation of new PdNPs and (NH)-C=O after loading. The covalent bond of, resulting in a new absorption peak.

Looking at the infrared spectra of the carrier and catalyst in Figure 4 (b) can be found that a new feature absorption peak appears at 1651 cm-1 after the load PdNPs, which is due to the formation of a new co-price key between PdNPs and (NH)-C-O after the load, thus creating a new absorption peak.

A new characteristic absorption peak at 1651 cm-1 can be found by observing the infrared spectrum of support and catalyst in Fig. 4 (b). This is due to the formation of a new covalent bond between (NH) - C = O and pdnps after loading.<br>