Ru Promoted MgO and Al-Modified MgO for Ethanol Upgrading

Mg-containing oxides are widely studied as effective catalysts for ethanol upgrading due to their capacity to promote dehydrogenation and coupling reactions. In such systems, the dehydrogenation of ethanol to acetaldehyde is thought to be the rate-determining step, so that the addition of dehydrogenation promoters onto the oxides could be a good way of optimizing the catalysts. Herein, we propose a systematic screening of different catalysts (MgO, Ru/MgO, Mg x AlO y , and Ru/Mg x AlO y ) in order to understand the roles of Ru and of the oxides in the several parallel reactions that occur in the systems. We investigated the catalysts by spectroscopic, textural and bench-scale techniques to correlate microscopic results with macroscopic findings. The insertion of Al into the MgO framework improved activity and product distribution towards ethene. Ru increased ethanol conversion in the systems, but directed the product distribution towards methane.