Gold Supported on Strontium Surface-Enriched CoFe2O4 Nanoparticles: a Strategy for the Selective Oxidation of Benzyl Alcohol

The synthesis of efficient and reusable gold-based catalysts for the selective oxidation of alcohols is a strategy for the development of green processes. Pre-formed nanoparticles syntheses are an easy way to produce controlled-nanosized gold materials; however, the selection of a support is not trivial. Herein, we proposed a CoFe2O4 support enriched with Sr(OH)2, which holds remarkable properties and is suitable for the synthesis of a stable gold-based catalyst for the oxidation of benzyl alcohol. We suggested that the interaction between the CoFe2O4 and the Sr(OH)2 is highly important for the performance of the catalyst. Under the base-free condition of 2.5 h, 100 ºC and 2 bar of O2, the catalyst reached 58% of conversion with 76% of selectivity to benzaldehyde. With K2CO3 addition, the conversion and selectivity to benzaldehyde increased to 87% and 88%, respectively. Any gold leaching was detected in 5 successive runs, attesting the noticeable stability that the catalyst presents. This work provides great potential for the selective oxidation of alcohols with high activity since the magnetic properties of the catalyst provide an easy route and allows the separation of the medium reaction. In addition, we are here proposing an important interaction between the Sr(OH)2 and the magnetic nanoparticles.