Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactiv...

Different surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity of probe molecules, assuming they specifically react with unique sites. In case of methanol synthesis catalysts, the Cu surface area is one of the crucial parameters in catalyst design and was for over 25 years commonly determined using diluted N2O. To disentangle...

Complementary in situ X-ray photoelectron spectroscopy (XPS), X-ray diffractometry, and environmental scanning electron microscopy are used to fingerprint the entire graphene chemical vapor deposition process on technologically important polycrystalline Cu catalysts to address the current lack of understanding of the underlying fundamental growth mechanisms and catalyst interactions. Graphene f...

Copper nanoparticles were synthesized on multiwall carbon nanotubes, (Cu)/(MWCNTs), based on solvothermal method. The used reagents include MWCNTs, cupric nitrate trihydrate (Cu (NO3)2.3H2O), diethylene glycol (DEG), diethanol amine. Characterization of Cu/MWCNTS nanoparticles was performed by techniques of Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction sp...

For carbon nanotube-based electronics to achieve their full performance potential, it is imperative to minimize the contact resistance between macroscale metal contacts and the carbon nanotube (CNT) nanoelectrodes. We have developed a three-dimensional electrode platform that consists of carbon nanofibers (CNFs) that are directly grown on a metal contact, such as copper (Cu). Carbon nanofiber m...

Ethanol synthesis from CH4 and syngas on a Cu-Co/TiO2 catalyst is studied using experiments, density functional theory (DFT) and microkinetic modelling. The experimental results indicate that the active sites of ethanol synthesis from CH4 and syngas are Cu and CoO, over which the ethanol selectivity is approximately 98.30% in a continuous stepwise reactor. DFT and microkinetic modelling results...

The direct formation of new C–C bonds through photocatalytic oxidative coupling from low reactive sp C–H bonds using environmentally benign and cheap oxygen as oxidant is an important area in sustainable chemistry. By incorporating the photoredox catalyst [SiW11O39Ru(H2O)] 5 into the pores of Cu-based metal–organic frameworks, a new approach for merging Cu-catalysis/Ru-photocatalysis within one...

Mechanistic insight into the semihydrogenation of 1-butyne and 2-butyne on Cu nanoparticles supported on partially dehydroxylated silica (Cu/SiO2-700) was obtained using parahydrogen. Hydrogenation of 1-butyne over Cu/SiO2-700 yielded 1-butene with ≥97% selectivity. The surface modification of this catalyst with tricyclohexylphosphine (PCy3) increased the selectivity to 1-butene up to nearly 10...

in the present study, the effects of calcium doping on the performance of the co-precipitated cu-mgo catalysts prepared with different calcium loadings in the selective hydrogenation of furfuraldehyde were investigated. the results proved that the addition of this promoter had a remarkable impact on the catalytic performance. the conversion of furfuraldehyde enhanced up to 83% and the furfuryl ...

The lifetime (200 h) of a Cu/SiO(2) catalyst under DMO-ethanol feedstock is 20 times longer than that (10 h) of the catalyst under DMO-methanol feedstock without any modification of the catalyst. The stabilization effect of ethanol on the active centers can effectively slow down the agglomeration of copper particles during the hydrogenation process.