ORTHO-SELECTIVE METHYLATION OF PHENOL OVER Ni1-XCoXFe2O4 (X=0.0,0.5 &1.0) TYPE FERRITE SYSTEM IN THE PRESENCE OF MAGNETIC FIELD

ABSTRACT

Vapor phase methylation of phenol with methanol has been studied over Ni_1-xCo_xFe₂O₄ (x=0.0,0.5 &1.0) in the temperature range 573-673K in a fixed bed down flow reactor in the presence of magnetic field. Methylation of phenol yield ortho-cresol and 2,6 xylenol as the major products. Phenol conversion and individual selectivity for ortho-cresol and 2,6-xylenol depends on the catalysts Ni²⁺/Co²⁺ ionic composition and applied magnetic field strength. A maximum yield of 75.2% and 13.2% were obtained for ortho-cresol and 2,6 xylenol respectively at 623K, methanol to phenol molar ratio, 5 and 0.4h^-1weight hour space velocity. The acidity of catalyst depends on the Ni²⁺/Co²⁺ ionic composition, when x=0 the catalyst is weakly acidic and favor ortho-cresol formation, and when x=1 the catalyst is moderately acidic and 2,6-xylenol is favored. Magnetic field suppresses consecutive methylation; as a result ortho-cresol is formed in higher yield. The catalyst characterization was made by XRD, FTIR, BET-SA and NH₃-TPD methods. The

results are discussed in terms of Ni²⁺/Co²⁺ ionic composition, acidity of catalysts and magnetic field strength. 

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