MOF-derived electron-transfer enhanced homogeneous PdO-rich Co3O4 as a highly efficient bifunctional catalyst for sodium borohydride hydrolysis and 4-nitrophenol reduction.

Developing a bifunctional catalyst with low cost and high catalytic performance in NaBH4 hydrolysis for H2 generation and selective reduction of nitroaromatics will make a significant impact in the field of sustainable energy and water purification. Herein, we report a homogeneously dispersed high-valence Pd oxide-rich Co3O4 polyhedral catalyst (PdO-Co3O4 ) with concave structure by metal-organic frameworks templated synthesis method. The results show that the PdO-Co3O4 catalyst has an exceptional turnover frequency (3325.6 molH2 min-1 molPd-1 ), low activation energy (43.2 kJ mol-1 ), and reasonable reusability in catalytic H2 generation from NaBH4 hydrolysis. Moreover, the optimized catalyst also shows excellent catalytic performance in NaBH4 selective reduction of 4-nitrophenol to 4-aminiphenol with a high first-order reaction rate of ca . 1.31 min-1 . These excellent catalytic properties mainly ascribe to the porous concave structure, monodispersed Pd-oxide, as well as the unique synergy between PdO and Co3O4 species that result in a large specific surface area, high conductivity, and fast solute transport and gas emissions.