Novel molybdenum–cerium based heterogeneous catalysts for efficient oxidative coupling of benzylamines under eco-friendly conditions

Hydrogenated Cu2O\Au@CeO2 Z-scheme catalyst for photocatalytic oxidation of amines to imines

Hydrogenated Cu₂O\Au@CeO₂ Z-scheme yolk–shell photocatalysts have been prepared, which exhibited significantly enhanced visible light photocatalytic oxidation activity when converting amines to imines.

Synthetically Tuned Atomic Ordering in PdCu Nanoparticles with Enhanced Catalytic Activity toward Solvent-Free Benzylamine Oxidation

Synthesis of ordered compounds with nano size is of particular interest for tuning the surface properties with enhanced activity and selectivity toward various important industrial catalytic processes. In this work, we synthesized ordered PdCu nanoparticles as highly efficient catalyst for the solvent-free aerobic oxidation of benzylamine. The Pd_xCu_1-x catalysts with different chemical compositions (x = 0, 0.25, 0.4, 0.5, 0.6, 0.75, 1) were prepared by polyol method using NaBH₄ as a reducing agent and were well-characterized by X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM) energy-dispersive analysis of X-rays, and X-ray absorption fine structure. The effect of different metal concentrations of Pd and Cu on the formation of Pd_xCu_1-x nanoparticles was investigated. The XRD and TEM confirmed the formation of ordered PdCu intermetallic phase with body-centered cubic (BCC) structure for the synthetic composition of Pd/Cu = 1:1. For compositions x = 0, 0.25, 0.75, and 1, Pd_xCu_1-x alloy with face-centered cubic (FCC) structure was observed, whereas mixed phase of BCC and FCC was observed for x = 0.4 and 0.6. The use of strong reducing agent (NaBH₄) was essential to synthesize PdCu ordered phase compared to weak reducing agents such as oleylamine and ascorbic acid. The PdCu nanocatalyst with ordered structure (BCC) showed excellent catalytic activity compared to Pd_xCu_1-x alloy nanoparticles with FCC structure. The atomic ordering in the PdCu intermetallic was the driving force for the enhancement in the catalytic activity with high benzylamine conversion of 94.0% and dibenzylimine selectivity of 92.2% compared to its monometallic and alloy counterparts. Moreover, ordered PdCu alloy showed good recyclability and activity toward the oxidation of different amines.

Ruthenium-catalyzed deaminative redistribution of primary and secondary amines

A ruthenium–hydride complex, [Ru(H)(Cl)(CO)(PCy₃)₂], was found to be active in the highly selective redistribution of primary and secondary amines bearing an α-hydrogen atom.