Selective ortho-methylation of phenol with methanol over copper manganese mixed oxide spinel catalysts

Satyanarayana Reddy, A. ; Gopinath, Chinnakonda S. ; Chilukuri, Satyanarayana (2006) Selective ortho-methylation of phenol with methanol over copper manganese mixed oxide spinel catalysts Journal of Catalysis, 243 (2). pp. 278-291. ISSN 0021-9517

Full text not available from this repository.

Official URL:

Related URL:


Methylation of phenol with methanol as an alkylating agent to produce 2,6-xylenol was investigated over copper manganese mixed oxide spinels, CuxMn3-xO4 (x=0, 0.25, 0.5, 0.75, and 1) prepared through co-precipitation. The catalytic activity strongly depends on the composition, acid-base properties, and structural stability. Various parameters, including catalyst composition, reaction temperature, feed composition, and durability of the catalyst during methylation, were investigated. Mainly o-cresol and 2,6-xylenol, along with small amounts of mesitol, were found in the product. A high ortho-selectivity of 100%, with 2,6-xylenol selectivity of 74%, was observed over Cu0.25Mn2.75O4 at 673 K. These catalysts were investigated using various techniques, including BET surface area, XRD, DRS UV-vis, TPD of NH3 and CO2, TPR, and X-ray photoemission spectroscopy (XPS). Powder XRD of the catalysts revealed the formation of copper-manganese spinels with hausmannite (Mn3O4) tetragonal structure, for x=0-0.5, whereas an increase in copper content (x>0.5) led to the formation of cubic Cu1.5Mn1.5O4 phase. DRS UV-vis, and FTIR further supported the changes in structural phases observed by XRD. Temperature-programmed desorption of CO2 and NH3 showed that the catalysts have strong basicity along with weak acidity when x=0 and 0.25. XPS and XAES analysis revealed the presence of only Cu2+ ions in fresh sample with x=0.25, whereas for x=1.0, both Cu1+ and Cu2+ were observed. The deactivation of the catalysts is attributed to structural changes occurring during the reaction. Catalytic activity is correlated with structure, as well as with acid-base properties.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
Keywords:Phenol Methylation; Ortho-alkylation; 2,6-Xylenol; Spinels; Copper-manganese oxides; Acidity-basicity
ID Code:81625
Deposited On:07 Feb 2012 05:19
Last Modified:07 Feb 2012 05:19

Repository Staff Only: item control page