Copper‐based high‐entropy oxide aerogel for chemoselective hydrogenation reaction

Abstract High‐entropy oxide aerogels (HEOs), combining the advantages of polymetallic oxides and aerogels, are novel materials with great prospect for catalytic applications. However, the preparation of single‐phase HEOs remains a great challenge. Herein, we report a general strategy for the preparation of ultralight 3D porous HEOs by combining a gelation strategy and a high‐temperature calcination process. The resulting CuFeCoAgPdO x has the structural and morphological advantages of a HEO and an aerogel and exhibits excellent selectivity (100%), full conversion (>99% yield) in the selective hydrogenation of 4‐nitrostyrene. In situ Fourier transform infrared spectroscopy (FT‐IR) and gas chromatography confirm that the synergistic effect of the HEOs can preferentially reduce the NO 2 group rather than the CC bonds in 4‐nitrostyrene. The synergistic effect of CuFeCoAgPdO x and the hydrogenation mechanism were revealed. This study provides a new idea for the design of efficient nitroaromatic hydrogenation catalysts.