A Highly Active and Reusable Multicomponent high Entropy Metal Oxide Catalyst for Nitroarenes Hydrogenation

It is well known that multicomponent catalysts can improve catalytic performance, however their rational design and precise control of catalytic activities by varying the composition of the elements is challenging. Herein, we present a facile and scalable synthetic strategy for production of senary and septenary metal oxide nanoparticles with a chemical composition of MSbOx and MSb2Ox (M: Fe, Ni, Co, Cu, and Zn). All samples were formed in a tetragonal crystal structure with space group 136 and crystallographic symmetry P42/mnm while the details of their constituent unit cells are different, belonging to rutile or trirutile structures. These nanocomposites have an oxygen vacancy-rich construction with uniform elemental distributions that produce various surface functionalities. They showed instantaneous hydrogenation catalytic performance for reduction of 4-nitrophenol to 4-aminophenol at room temperature. Among our samples, the senary catalyst with MSbOx chemical composition showed better durability and reusability owning to its morphological and microstructural properties. It showed 100% conversion of 4-nitrophenol to 4-aminophenol within 4 min at the 18th run without any by-products.