Copper-based Catalysts for Synthesis of Methylamines: The Effect of the Metal and the Role of the Support

Abstract

Three Cu-based catalysts supported in different materials were prepared. The textural properties showed that the thermal treatment and the presence of CuO resulted in decrease of BET area. The surface areas of the Cu on alumina and zeolite decay with Cu addition, which can be attributed to the formation of CuO particles, blocking the pores. Contrary, the based like-hydrotalcite catalysts surface areas increased, which may be attributed to the destruction of the structure and formation of oxide mixtures. The acid sites with moderate strength favored the methylamines production, due to the easier desorption of products. The metallic sites affect the reaction since they provide a decrease in desorption temperature of the amines and enhance the disproportionation. The metallic sites in the based like-hydrotalcite catalysts Cu/Mg-Al enhance the formation of methylamines. The Cu/Al 2 O 3 was more active and stable than the other Cu based catalysts.

Advancements in the Synthesis and Applications of Cationic N‐Heterocycles through Transition Metal‐Catalyzed C−H Activation

“…[47][48][49] Treatment of the isolated Rh-com-plex with an alkyne in the absence of any other additives provided the expected isoquinolinium salt product. Surprisingly,c oordination of the dimethylamine to the Rh I center was found in the single-crystal structurea nalysis.…”

Structural Transformation of Cu–Mg–Al Mixed Oxide Catalysts Derived from Hydrotalcites During Shift Reaction

“…The 30CuMgHTc sample presented a main reduction peak at 303°C, attributed to the reduction CuO ? Cu°, and a small shoulder at 334°C, associated with the reduction of copper species of different reducibilities, which were not detected in XRD patterns probably due to the great dispersion of the oxide mixture [18]. For 42CuMgHTc catalyst only one peak at 347°C was detected, related to the reduction of CuO to Cu°.…”

Research on the N-alkylation of morpholine with alcohols catalyzed by CuO–NiO/γ–Al2O3

“…So, part of the copper oxide on the surface of the catalyst is reduced to a lower valence state, and a Cu 0 -Cu ? layer may form on the surface of the catalyst [22][23][24][25]. The mixed catalyst is more stable than the monometallic one for the association of copper and nickel increases the metal surface area, the hydrogen adsorption and storage, and the acidity sites.…”