Earth-abundant nanocatalysts are actively searched to replace expensive noble metal catalysts for a number of essential processes. Here, Cu catalysts have been designed based on manganese oxide octahedral molecular sieve (OMS-2) supports to optimize the catalytic activity in nitrophenol reduction, CuAAC click reaction and terminal alkyne homocoupling. A correlation has been established between the different synthetic strategies and catalytic activities. CuO_x/OMS-2 has also been found an efficient catalyst for the homocoupling of terminal alkynes, click reaction and the reduction of 4-nitrophenol, 2,4-dinitrophenol and 4-nitrobenzene diazo tetrafluoroborate with high activity, whereas Cu-OMS-2 only shows poor catalytic activity for reduction and click reaction, and no catalytic activity for homocoupling.

OMS-2-based nanocomposites doped with tungsten were prepared for the first time and their remarkably enhanced catalytic activity and recyclability in aerobic oxidative dehydrogenation of N-heterocycles were examined in detail. Many tetrahydroquinoline derivatives and a broad range of other N-heterocycles could be tolerated by the catalytic system using a biomass-derived solvent as a reaction medium. Newly generated mixed crystal phases, noticeably enhanced surface areas and labile lattice oxygen of the OMS-2-based nanocomposite catalysts might contribute to their excellent catalytic performance. Moreover, a kinetic study was extensively performed which concluded that the dehydrogenation of 1,2,3,4-tetrahydroquinoline is a first-order reaction, and the apparent activation energy is 29.66 kJ mol⁻¹.

A rapid solvent-free ball-milling method was developed to prepare a hydrophobic hydrotalcite supported Cu–Mn mixed oxide catalyst (Cu–Mn/HT). The mechanochemically prepared catalyst exhibited high catalytic activity and recyclability towards the aerobic synthesis of 2-acylbenzothiazoles and quinoxalines in green medium ethanol compared with the ones synthesized via grinding and wet-impregnation. Moreover, control experiments showed that the catalyst was successfully used in green oxidative esterification and coupling as well. Cu–Mn/HT was characterized by BET, ICP, XRD, XPS, SEM and TEM, which indicated that more surface oxygen vacancies and formed CuMn₂O₄ species on HT might contribute to the catalytic activity.