Effect of the composition and acidity of supported sulfide catalysts on their activity and deactivation in guaiacol hydrodeoxygenation

The following catalysts have been prepared: XMo 6 HPC/Al 2 O 3 , based on Anderson-type heteropoly compounds (HPCs), with the general formula XMo 6 HPC in which the central heteroatom is a fourth-row p - or d -element (X = Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Al); Co 6 (CA)-PMo 12 /support, based on 12-phosphomolybdic acid and cobalt citrate, in which the support is Sibunit, Al 2 O 3 , carbonized alumina, or alumina modified with zeolite ZSM-5 or Beta. The supports and catalysts have been characterized by low-temperature nitrogen adsorption, X-ray powder diffraction, and temperature-programmed ammonia desorption. The properties of the catalysts in guaiacol hydrodeoxygenation (HDO) have been investigated in a flow reactor at 260°C, 3.0 MPa, a feed hourly space velocity of 80 h −1 , and H 2 : feed = 500 L/L. The activity of the XMo 6 HPC/Al 2 O 3 catalysts depends on the kind of heteroatom X: the most active catalysts are those with X = Co or Ni, and the least active ones are those with X = Cu. There is a linear antibatic correlation between the HDO activity of the catalysts and the acidity of the support. The lower activity of the zeolite-containing catalysts is due to their high degree of deactivation. Catalysts supported on carbonized alumina, which proved to be most active and most resistant to deactivation, are recommended for the HDO of vegetable raw materials.