New Design PdNi Heterogeneous Nanocatalysts for the Direct Synthesis of Hydrogen Peroxide

Abstract

Hydrogen peroxide (H2O2) is a widely used chemical as an eco-friendly oxidizing agent, with water being the only byproduct of oxidation in applications like bleaching pulp and paper, making electronic semiconductors, chemical and detergent synthesis, and wastewater treatment. The direct synthesis approach is preferred to provide the environmentally friendly production of H2O2 for market requirements. Bimetallic PdNi nanocatalysts were chosen for this study because of their catalytic activity and the structural characteristics of the material system. First, for the development of order-structured bimetallic PdNi nanocatalysts based on mesoporous carbon template after hydrogen-assisted heat treatment at 750∘C. The transformation of the disordered structure into ordered intermetallically structured PdNi alloys with higher alloying extents was confirmed by X-ray absorption spectroscopy (XAS) and high-resolution transition electron microscopy (HR-TEM). Then, to improve the oxygen oxidation reaction, two-electron pathway selectivity was used by TiO2-C as a support-ordered structure material to facilitate strong metal-support interactions. XAS and X-ray photoelectron spectra (XPS) techniques show more clear evidence of metal-support interactions with electron transfer from defects in the TiO2-C support to the ordered alloyed PdNi nanocatalysts, resulting in record productivity and selectivity of H2O2 production at ambient conditions. The results demonstrated in this study will enlighten a reliable design of new heterogeneous nanocatalysts with ordered structure. Electron transfer between hybrid support and active sites can clarify the catalytic behavior and prompt further research during the direct synthesis of hydrogen peroxide. Keywords: hydrogen peroxide, direct synthesis, heterogeneous nanocatalysts PdNi, TiO2-C