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 molH2O2 kgcat−1 h−1 and 85.5%, respectively, superior to the PdAu/TiO2 catalyst (450.2 molH2O2 kgcat−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.