Direct Synthesis of a-Methoxyphenylacetic Acid Via Tandem Catalysis from Styrene and Methanol with Co3O4/CuCo2O4 Heterostructures

Tandem catalysis as an exciting research frontier has recently aroused wide attention due to the eliminated intermediate work-up, improved production efficiency, decreased production cost and reduced waste discharge. The main challenge in this tandem catalytic approach is the exploiting of a bifunctional catalyst that can be effective for both reactions processed under the same reaction conditions in a single reactor. We herein report for the first time that in the presence of in-situ generated Co3O4/CuCo2O4 heterostructures (CCHS) as a heterogeneous catalyst, alpha-methoxyphenylacetic acid (MTPAA) can be produced via tandem catalysis from styrene and methanol by integrating the styrene epoxidation and subsequent nucleophilic ring-opening of styrene oxide (SO). The styrene conversion of 94.8% accompanied with a selectivity of 62.5% to MTPAA was achieved under the optimal reaction conditions. Consequently, a simple heterogeneous approach for the highly efficient and selective production of MTPAA has been established. This study highlights the great potential of bifunctional heterostructures composed of earth-abundant elements for the synthesis of valuable chemicals via tandem conversion of styrene and subsequent diverse SO ring-opening reactions.