A comparative study of the WO_x dispersion on Mn-promoted tungstated zirconia catalysts prepared by conventional and high-throughput experimentation

Conventional and high-throughput experimentation (HTE) techniques were used for the synthesis, characterization, and catalytic testing of Pt/Mn-WO_x-ZrO₂ materials. The catalysts were prepared by surfactant-assisted coprecipitation and screened for catalytic activity in a multi-channel fixed bed (MCFB) micro-reactor for the hydroisomerization of n-hexane. Conventional coprecipitation route leads mainly to the segregation of the WO₃ crystalline phase (XRD). On the other hand, the use of the automated HTE route allows the formation of catalysts with a highly dispersed WO_x phase on the zirconia surface and a high surface area (60-100 m²/g) when calcined at 800 °C (N₂ physisorption, XRD, Raman, UV-vis, HRTEM). These polytungstates with different coordination symmetry are accessible to the reactants and they lead to an increase in the catalytic activity and selectivity to the bi-ramified products (2,2-DMB and 2,3-DMB) in the n-hexane isomerization. In addition, it was found that the incorporation of Mn modifies the nanostructural properties of the tungstated zirconia favoring the catalytic activity of these materials.