Synergetic electrocatalytic activities towards hydrogen peroxide: Understanding the ordered structure of PdNi bimetallic nanocatalysts

Mesoporous carbon-template-supported novel-order face-centered cubic (fcc) structured bimetallic PdNi nanocatalysts were prepared for the ‘green synthesis’ of hydrogen peroxide (H2O2). Our results show that the alloy crystal structure of fcc-Pd050Ni050 can be structurally transformed into a face-centered tetragonal (fct) structure after hydrogen-assisted heat-treatment at 750 °C. Transformation of the fcc structure into the fct structure resulted in ordered intermetallically structured Pd050Ni050 alloys with higher alloying extents as confirmed by X-ray absorption spectroscopy (XAS) and high resolution TEM. In addition, an electrochemical detection method was developed for in situ measurement of direct H2O2 synthesis. The fct-Pd050Ni050 catalysts produced demonstrated both enhanced structural stability and higher productivity than the fcc structured nanocatalysts and in doing so potentially offer a cost-effective route to the direct synthesis of hydrogen peroxide. [Display omitted] •PdNi alloy with face-centered tetragonal structure was obtained after H2 treatment.•X-ray absorption spectroscopic analysis confirms the structural transformation.•Heterometallic bonding in ordered PdNi enhances the direct synthesis of H2O2.•An electrochemical method was developed to detect in-situ formation of H2O2.•fct-Pd050Ni050 gives much higher productivity than reported values in literature.