This paper reports on the catalytic oxidative cleavage of trans-1,2-cyclohexanediol with air, catalysed by supported Au NPs, as one of the steps of a new adipic acid synthesis process. Catalysts proved to be active, with a moderate cyclohexanediol conversion and selectivity to adipic acid close to 70%. The reaction network included several steps in sequence, amongst which the key one is the oxidation of the diol into 2-hydroxycylohexanone, which is then oxidised by air – even in the absence of a catalyst – to adipic acid and lesser amounts of lighter acids, i.e. glutaric and succinic acids. The oxidation of the second hydroxyl moiety in the diol would lead to the formation of 1,2-cyclohexanedione. The latter, however, is rapidly transformed into several by-products, especially glutaric acid, under the basic conditions which are necessary for allowing the reaction to occur at an acceptable rate. With Au-based catalysts, this undesired reaction occurs much more slowly than with the previously investigated Ru hydroxide catalysts. The nature of the support, either TiO2or MgO, also affected catalytic performance; the best performance was shown by the Au/MgO catalyst which, however, suffered from a remarkable deactivation, found to be due to both the increase in NPs size and the formation of carbonaceous residua on the catalyst surface.
The oxidative cleavage of trans-1,2-cyclohexanediol with O2: Catalysis by supported Au nanoparticles / Solmi, Stefania; Rozhko, Elena; Malmusi, Andrea; Tabanelli, Tommaso; Albonetti, Stefania; Basile, Francesco; Agnoli, Stefano; Cavani, Fabrizio. - In: APPLIED CATALYSIS A: GENERAL. - ISSN 0926-860X. - ELETTRONICO. - 557:(2018), pp. 89-98. [10.1016/j.apcata.2018.03.019]
The oxidative cleavage of trans-1,2-cyclohexanediol with O2: Catalysis by supported Au nanoparticles
SOLMI, STEFANIA;Rozhko, Elena;Malmusi, Andrea;Tabanelli, Tommaso;Albonetti, Stefania;Basile, Francesco;Cavani, Fabrizio
2018
Abstract
This paper reports on the catalytic oxidative cleavage of trans-1,2-cyclohexanediol with air, catalysed by supported Au NPs, as one of the steps of a new adipic acid synthesis process. Catalysts proved to be active, with a moderate cyclohexanediol conversion and selectivity to adipic acid close to 70%. The reaction network included several steps in sequence, amongst which the key one is the oxidation of the diol into 2-hydroxycylohexanone, which is then oxidised by air – even in the absence of a catalyst – to adipic acid and lesser amounts of lighter acids, i.e. glutaric and succinic acids. The oxidation of the second hydroxyl moiety in the diol would lead to the formation of 1,2-cyclohexanedione. The latter, however, is rapidly transformed into several by-products, especially glutaric acid, under the basic conditions which are necessary for allowing the reaction to occur at an acceptable rate. With Au-based catalysts, this undesired reaction occurs much more slowly than with the previously investigated Ru hydroxide catalysts. The nature of the support, either TiO2or MgO, also affected catalytic performance; the best performance was shown by the Au/MgO catalyst which, however, suffered from a remarkable deactivation, found to be due to both the increase in NPs size and the formation of carbonaceous residua on the catalyst surface.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.