Nickel- and Molybdenum-Containing Catalysts for Direct Synthesis of Propylene from Ethylene: Effect of the Support

Polyfunctional Ni- and Mo-containing catalysts are prepared by sequentially impregnating a support (SiO 2 , Al 2 O 3 , B 2 O 3 –Al 2 O 3 , SO_4^2 - /Al 2 O 3 , SO_4^2 - /ZrO 2 ) using solutions of corresponding salts with intermediate steps of drying at 120°C and calcination at 500–550°C. X-ray powder diffraction, temperature programmed reduction, UV-VIS diffuse reflectance spectroscopy, and electron spin resonance spectroscopy are used to study physicochemical properties of the prepared catalysts. The catalysts are tested in the direct synthesis of propylene from ethylene at an atmospheric pressure, 200°C and an ethylene weight hourly space velocity of 0.5 h −1 . The highest conversion of ethylene and yield of propylene are achieved for a sample based on borated alumina, due to the formation of active sites of ethylene dimerization, Ni 2+ ions bound to acid sites of the support, and active sites of metathesis (surface monomolybdate compounds).