Identification of C2-C5 products from CO2 hydrogenation over PdZn/TiO2-ZSM-5 hybrid catalysts - data

<p>A PdZn/TiO₂ methanol catalysts was physically mixed with different ZSM-5 zeolites with different acidity (Si/Al ratio of 23, 50 and 80). The phisical mixture of two different catalysts for tandem reactions are known as hybrid catalysts. PdZn/TiO₂-ZSM-5 hybrid catalysts were employed for the CO₂ hydrogenation to CH₃OH, consecutive CH₃OH dehydration to dimethyl ether (DEM) and further CH₃OH/DME conversion to hydrocarbons (20 bar, CO₂/H₂/N₂ = 1/3/1, 30 ml min^-1, 240-360 °C).<br></p><p>PdZn/TiO₂ catalyst prior and after reaction was characterised by XRD, XPS and XAS. Characterisation shows that the bulk PdZn phase is stable during reaction, however, some surface PdZn decomposition to Pd and ZnO might occur.</p><p>CH₃OH produtivity over PdZn/TiO₂ is limited by equilibrium above 270-300 °C, the combination with an acid catalyst (ZSM-5 zeolite) promotes CH₃OH dehydration to DME, increasing the total CH₃OH productivity. CH3OH and DME react over acid sites on ZSM-5 through the MTH and DMETH to produce olefins. Synthesise olefins however undergo further hydrogeation to the corresponding alkanes, likely over PdZn hydrogenation active sites. Thus, restricting chain growth for the production of hydrocarbons on the gasoline range.</p><p>Research results based upon these data are published at https://doi.org/10.1039/D0FD00135J</p><p><br></p>