Kinetic and FTIR studies of 2-methyltetrahydrofuran hydrodeoxygenation on Ni₂P/SiO₂

The hydrodeoxygenation of 2-methyltetrahydrofuran (2-MTHF) at a medium pressure of 0.5 MPa is studied over a Ni₂P/SiO₂ catalyst. Contact time studies show the formation of n-pentanal, 1-pentanol, 2-pentanone, 2-pentanol, and 2-pentene, as reaction intermediates and the production of pentane and butane as major products. The results are consistent with adsorption of 2-MTHF followed by rate-determining ring-opening to form either 1-pentoxide or 2-pentoxide alkoxide intermediates. Subsequent hydrogen-transfer steps produce the various intermediates, a decarbonylation step of the pentanal forms n-butane and CO, and further hydrodeoxygenation steps result in n-pentane. Fitting of the results using a rake mechanism that considers adsorbed intermediates gives excellent agreement with experimental data, and agrees with a simulation with a simpler first-order model. The more detailed rake analysis indicates that the surface species from the 1-pentoxide intermediate are ten-fold more plentiful than those produced from the 2-pentoxide intermediate. In situ infrared measurements support this reaction mechanism.