Abstract

A custom-made plug-flow fixed-bed catalytic reactor was designed and constructed to examine the behaviour of Pd catalysts during a Suzuki-Miyaura cross-coupling reaction. Spatial-temporal resolution of catalyst activation, deactivation and (possibly) leaching processes can be obtained by single-pass experiments. Subsequent deployment of the flow reactor in a X-ray absorption spectroscopy beam line allowed the catalyst bed to be mapped axially, revealing speciation of Pd(0) and Pd(II) species along the catalyst bed, distinct phase changes and unusual redox bi-stabilities.