Enhancing the catalytic performance of PdAu catalysts by W-induced strong interaction for the direct synthesis of H2O2

Abstract

The addition of non-noble metals is a promising method for developing PdAu-based catalysts for the direct synthesis of H₂O₂. Here, we prepared W-promoted PdAu/TiO₂ to enhance the synthesis of H₂O₂. The PdAu/WO₃–TiO₂ catalyst, with pre-loading of W followed by PdAu presented the best performance with a H₂O₂ yield and selectivity as high as 662.6 mol_H2O2 kg_cat⁻¹ h⁻¹ and 85.5%, respectively, superior to the PdAu/TiO₂ catalyst (450.2 mol_H2O2 kg_cat⁻¹ h⁻¹ and 73.9%). It was found that the W-induced strong interaction with PdAu is the key to the enhanced catalytic performance, with WO₃ species partially encapsulating the PdAu particles, and inducing the formation of surface PdO. However, excessive addition of W would completely coat the active metal PdAu and reduce the H₂O₂ synthesis. Furthermore, the W promoter effect was demonstrated to be carrier-dependent. This work proves the facilitation mechanism of W and provides a promising strategy for developing PdAu-based catalysts for the direct synthesis of H₂O₂.