Insights in supported rhenium carbide catalysts for hydroconversion of lignin-derived compounds

Rhenium supported over activated carbon (AC) was carburized under different temperatures (from 500 to 700 °C) under a mixture of H₂/C₂H₄ (75/25). Resulting catalysts were characterized by N_2-sorption, CO chemisorption, temperature programed reduction (TPR), ammonia temperature programed desorption (TPD-NH₃), STEM, and XPS and catalytic properties were measured in a batch reactor at 350 °C, 5.0 MPa for the hydrodeoxygenation (HDO) of guaiacol. Results have shown that Rhenium was gradually reduced and carburized upon increasing the temperature. From 650 °C, a Re_xC phase was obtained and transformed into ReC at 700 °C. Re_xC was the most active phase obtained and maximum yield in benzene of 51% was reached at complete conversion. ReC phase showed to inhibit the hydrogenolysis of phenol into benzene.