Theoretical insights into the sites and mechanisms for base catalyzed esterification and aldol condensation reactions over Cu

Tracing the reactivity of single atom alloys for ethanol dehydrogenation using ab initio simulations

A full DFT parameterized MKM is used to accurately predict the reactivity trend for ethanol dehydrogenation reaction on SAAs.

Supported Cobalt Catalysts for Acceptorless Alcohol Dehydrogenation

The acceptor-less dehydrogenation of 2-octanol was tested over cobalt supported on Al₂ O₃ , C, ZnO, ZrO₂ and various TiO₂ substrates. The catalysts were characterized by ICP, XRD and TGA-H₂ . For Co/TiO₂ P25, the effects of passivation, aging (storage at room temperature), and in situ activation under H₂ were investigated. The catalysts must be tested shortly after synthesis in order to prevent deactivation. Cobalt supported on TiO₂ P25 was the most active and 69 % yield of 2-octanone was obtained, using decane as a solvent. Selectivities for 2-octanone were observed in the range of 90 % to 99.9 %. Small amounts of C16 compounds were also formed due to aldol condensation/dehydration reactions. The catalysts exhibited higher conversion in the dehydrogenation of secondary alcohols (65-69 %), in comparison to primary alcohols (2-10 %). The dehydrogenation of 1,2-octanediol led to 1-hydroxy-2-octanone, with a selectivity of 90 % and 69 % for Co/TiO₂ P25 and Co/TiO₂ P90, respectively.

A ZrO2-RGO composite as a support enhanced the performance of a Cu-based catalyst in dehydrogenation of diethanolamine

The sintering resistance of supported Cu nanoparticle (NP) catalysts is crucial to their practical application in the dehydrogenation of diethanolamine (DEA). In this paper, co-precipitation, hydrothermal synthesis, and sol–gel condensation are used to form a new support material through chemical bonding between graphene oxide and ZrO₂. The composite carriers prepared by the three methods are mixed with copper nitrate and ground using a ball mill. A series of Cu/ZrO₂-reduced graphene oxide (RGO) composites were prepared by calcination under nitrogen at 450 °C for 3 h and hydrogen reduction at 250 °C for 4 h. The conversion of DEA to iminodiacetic acid (IDA) reached 96% with the Cu/ZrO₂-RGO catalyst prepared by hydrothermal synthesis. The conversion rate of DEA is more than 80% following the reuse of the CZG-2 catalyst for twelve cycles. The various physicochemical characterization techniques show that the Cu/ZrO₂-RGO layered and wrinkled nanostructures can improve catalytic stability and suppress the sintering of the supported Cu NPs during the catalytic dehydrogenation of diethanolamine. A synergistic effect between the RGO and the Cu nanoparticles is observed. The Cu nanoparticles with RGO have a better dispersibility, and a new nano-environment is created, which is the key to improving the efficiency of diethanolamine dehydrogenation. These new Cu/ZrO₂-RGO catalysts show increased durability compared to commercially produced Cu/ZrO₂ catalysts and show promise for practical applications involving diethanolamine dehydrogenation.

A Cu/ZrO₂-RGO catalyst prepared by hydrothermal synthesis of a ZrO₂-RGO carrier has highly dispersed Cu nanoparticles and resistance to sintering.

Ethanol dehydrogenative reactions catalyzed by copper supported on porous Al–Mg mixed oxides

Mixed aluminum and magnesium oxides (AlMgO) prepared by means of an emulsion-mediated sol–gel method was impregnated with copper species and used in the ethanol dehydrogenative reactions to produce acetaldehyde and ethyl acetate.

Ethanol condensation at elevated pressure over copper on AlMgO and AlCaO porous mixed-oxide supports

The coupling of ethanol to produce C₄-compounds by Guerbet condensation at 325 °C was studied using porous mixed oxide catalysts of AlMgO and AlCaO prepared by the emulsion mediated method with and without the addition of Cu.

Superparamagnetic nanoparticles as a recyclable catalyst: a new access to phenol esters via cross dehydrogenative coupling reactions

CuFe₂O₄ superparamagnetic nanoparticles were utilized as a recyclable heterogeneous catalyst for the direct synthesis of chemical structures containing both phenol ester and benzothiazole moieties via cross dehydrogenative coupling reactions.