Mono- and bimetallic catalysts supported on MIL-53(Ga, Cr)

The materials under investigation are designed for the selective hydrogenation of acetylene, an important process in the "removal" of acetylene from the ethylene feed stream in petrochemical processes. Pd-based catalysts, which are widely used for this reaction, were synthesized on the surface and within the channels of the metal-organic framework (MOF) MIL-53, where the metal centers consist of Ga or Cr(III) atoms.
To address the primary drawback of Pd-based catalysts—overhydrogenation—bimetallic Pd-Ag nanoparticles with varying metal-to-metal ratios were synthesized. This approach, coupled with the potential intermetallic interactions between the nanoparticles and the framework centers, is expected to restrict excessive catalytic activity of the Pd centers. This limitation aims to prevent further hydrogenation of ethylene to ethane and reduce catalyst deactivation.
In situ X-ray absorption spectroscopy was employed as a powerful technique to investigate the structure of the new materials and the active phase of the Pd centers during the reaction.