Monolithic Mesh-Type Fe-Pd/γ-Al<sub>2</sub>O<sub>3</sub>/Al Bifunctional Catalysts for Electro-Fenton Degradation of Rhodamine B

Abstract

A novel Fe-Pd bifunctional catalyst supported on mesh-type γ-Al 2 O 3 /Al was prepared and applied in the degradation of Rhodamine B (RhB). The monolithic mesh-type Fe-Pd/γ-Al 2 O 3 /Al bifunctional catalyst could be separated from the solution directly and could synthesize H 2 O 2 in situ. The characterization results showed that Fe could improve the dispersion of Pd 0 , and the electronic interactions between Pd and Fe could increase the Pd 0 contents on the catalyst, which increased the productivity of H 2 O 2 . Furthermore, DFT calculations proved that the addition of Fe could inhibit the dissociation of O 2 and promote the nondissociative hydrogenation of O 2 on the surface of Fe-Pd/γ-Al 2 O 3 /Al, which resulted in the increasement of H 2 O 2 selectivity. Finally, the in-situ synthesized H 2 O 2 by Pd was furtherly decomposed in situ by Fe to generate •OH radicals to degrade organic pollutants. Therefore, Fe-Pd/ γ-Al 2 O 3 /Al catalysts exhibited excellent catalytic activity in the in-situ synthesis of H 2 O 2 and the degradation of RhB due to the synergistic effects between Pd and Fe on the catalyst. It provided a new idea for the design of bifunctional electro-Fenton catalysts. Ten cycles of experiments showed that the catalytic activity of Fe-Pd/γ-Al 2 O 3 /Al catalyst could be maintained for a long time.

Mechanism in chlorine‐enhanced Pd catalyst for H2O2in situ synthesis in electro‐Fenton system

“…Li et al 26 reported that Pd–Sn nanocrystals stimulated a noticeable enhancement in H 2 O 2 production due to their inhibition of decomposition and hydrogenation of H 2 O 2 . In our previous work, 27 a Fe–Pd bifunctional catalyst was successfully designed and applied in the EF degradation of Rhodamine B. Not only could Fe slightly inhibit OO bond dissociation to promote H 2 O 2 production on Pd, but it could also degrade Rhodamine B through Fenton reaction.…”