Conversion of 5-Methyl-3-Heptanone to C8 Alkenes and Alkane over Bifunctional Catalysts

A one-step catalytic process was used to catalyze the hydrodeoxygenation of 5-methyl-3-heptanone (C 8 ketone) to a mixture of 5-methyl-3-heptene, 5-methyl-2-heptene (C 8 alkenes), and 3-methyl heptane (C 8 alkane). High conversion of C 8 ketone to the desired products was achieved over a single bed of a supported catalyst (bifunctional heterogeneous catalyst) consisting of one transition metal (copper (Cu) or platinum (Pt)) loaded on alumina (Al 2O 3) under mild operating conditions (reaction temperatures were varied between 180 °C to 260 °C, and the pressure was 1 atm). The C 8 ketone was hydrogenated to 5-methyl-3-heptanol (C 8 alcohol) over metal sites, followed by dehydration of the latter on acid sites on the support to obtain a mixture of C 8 alkenes. These C 8 alkenes can be further hydrogenated on metal sites to make a C 8 alkane. The results showed that the main products over copper loaded on alumina (20 wt% Cu–Al 2O 3) were a mixture of C 8 alkenes and C 8 alkane in different amounts depending on the operating conditions (the highest selectivity for C 8 alkenes (~82%) was obtained at 220 °C and a H 2/C 8 ketone molar ratio of 2). However, over platinum supported on alumina (1 wt% Pt–Al 2O 3), the major product was a C 8 alkane with a selectivity up to 97% and a conversion of 99.9% at different temperatures and all H 2/C 8 ketone ratios. View Full-Tex