Inhibition of a Gold-Based Catalyst in Benzyl Alcohol Oxidation: Understanding and Remediation

Catalysts

Emmanuel Skupien¹  Rob J. Berger²  Vera P. Santos¹  Jorge Gascon¹  Michiel Makkee¹  Michiel T. Kreutzer³  Patricia J. Kooyman¹  Jacob A. Moulijn¹ 

[1] Catalysis Engineering, Chemical Engineering Department, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands; E-Mails:;Anaproc c/o Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands; E-Mail:;Product & Process Engineering, Chemical Engineering Department, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands; E-Mail:

关键词: gold;    catalysis;    benzyl alcohol;    oxidation;    deactivation;    inhibition;    mechanism;    kinetics;    modeling;   

DOI  :  10.3390/catal4020089

来源: mdpi

【 摘 要 】

Benzyl alcohol oxidation was carried out in toluene as solvent, in the presence of the potentially inhibiting oxidation products benzaldehyde and benzoic acid. Benzoic acid, or a product of benzoic acid, is identified to be the inhibiting species. The presence of a basic potassium salt (K₂CO₃ or KF) suppresses this inhibition, but promotes the formation of benzyl benzoate from the alcohol and aldehyde. When a small amount of water is added together with the potassium salt, an even greater beneficial effect is observed, due to a synergistic effect with the base. A kinetic model, based on the three main reactions and four major reaction components, is presented to describe the concentration-time profiles and inhibition. The inhibition, as well as the effect of the base, was captured in the kinetic model, by combining strong benzoic acid adsorption and competitive adsorption with benzyl alcohol. The effect of the potassium salt is accounted for in terms of neutralization of benzoic acid.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.