Evidence for production of surface formate upon direct reaction of CO with alumina and magnesia

• Published in: Journal of catalysis Vol. 105; no. 2; pp. 366 - 372
• Main Authors: Gopal, Pradip G., Schneider, Roger L., Watters, Kenneth L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.06.1987; Elsevier
• Subjects: Applied sciences; Catalysis; Catalysts: preparations and properties; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; Other techniques and industries; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Infrared spectrometry; Surface reaction; Magnesia; Reaction mechanism; Formate; Carbon monoxide; Alumina; Catalyst
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(87)90066-2

The observation of adsorbed formate ion produced by the reaction of CO with MgO or γ-Al 2O 3 surfaces at temperatures between 375 and 575 K is reported. Infrared bands observed near 1590, 1380, 1360, and 1050 are assigned to the fundamentals of adsorbed HCO 2 − ion on the basis of spectra that have been reported for formate ion in solution. The spectral bands and observed isotopic shifts for adsorbed formate produced by reaction of the oxide surface with CO agree with the spectra of formates produced by reaction of methanol or formic acid with the same surfaces. The intensity of IR bands due to formate produced by reaction of the oxide surfaces with CO depends upon the hydroxyl group concentration at the surface. A mechanism for conversion of CO to formate via a surface acylium ion is proposed.