The First Application of Palladium–Phosphorus Catalysts in the Direct Synthesis of Hydrogen Peroxide: Reasons for the Promoting Action of Phosphorus

• Published in: Kinetics and catalysis 2023-12, Vol.64 (6), p.804-814
• Main Authors: Belykh, L. B., Skripov, N. I., Sterenchuk, T. P., Akimov, V. V., Tauson, V. L., Likhatski, M. N., Milenkaya, E. A., Kornaukhova, T. A., Schmidt, F. K.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Chemical synthesis; Chemistry; Chemistry and Materials Science; Electron states; High resolution electron microscopy; Hydrogen peroxide; Inductively coupled plasma; Inductively coupled plasma mass spectrometry; Mass spectrometry; Palladium; Particle size; Phosphorus; Photoelectrons; Physical Chemistry; Solid solutions; Surface layers; X ray photoelectron spectroscopy; X ray powder diffraction
• ISSN: 0023-1584; 1608-3210
• DOI: 10.1134/S0023158423060022

The main reasons for the promoting effect of phosphorus on the properties of Pd–P/ZSM-5 catalysts during direct synthesis of H 2 O 2 from H 2 and O 2 under mild conditions are considered based on the data obtained by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and inductively coupled plasma mass spectrometry (ICP MS). The introduction of phosphorus in the catalyst affects the particle size and the electronic state of palladium in the surface layer, as well as the surface concentration of the phosphate and phosphite ions. The yield of H 2 O 2 increases when the particle size of the Pd–P catalysts decreases, when the side process of H 2 O 2 decomposition is inhibited by the phosphate and phosphite surface ions, and when the hydrogen solubility in the solid solutions of phosphorus in palladium decreases.