(544bt) The Role of Hydroxyl Groups in Carbon Monoxide Oxidation over Copper-Titanium Dioxide Catalysts

Increasing the pH substantially promotes the reaction rate of carbon monoxide oxidation in liquid phase because of the abundant hydroxyl groups[1]. Meanwhile increases in the moisture content begin to suppress the reaction rate, while co-feed water concentration is further increased [2]. Recently we reported that the hydroxyl groups supplied through the support surface inhibited the reaction rate for carbon monoxide oxidation in gas phase [3]. Copper-titanium dioxide synthesized by wet-impregnation method were characterized with X-Ray diffraction, infrared spectroscopy and hydrogen temperature programmed reduction as well as kinetics studies. The hydroxyl groups on the catalyst surface are essential in determining the nature of intermediates formed upon carbon monoxide and the oxidation state of copper. The hydroxyl groups favored the formation of copper(I) species. The excess hydroxyl groups did not alter the reaction pathway but affected the carbon monoxide chemisorption and oxidation.

References:

[1]M.S. Ide, R. J. Davis, Acc.Chem.Res. 2014 (47) 825.

[2]M. Date, M. Haruta, J.Catal. 2001 (201) 221.

[3]G. Q. Cao, N. Yi, Chem. Comm. 2018 In revision.