Haydar Göksu

Eco-friendly hydrogenation of aromatic aldehyde compounds by tandem dehydrogenation of dimethylamine-borane in the presence of a reduced graphene oxide furnished platinum nanocatalyst

In this study, highly monodisperse platinum nanoparticles supported on reduced graphene oxide in the presence of tripentylamine (TPA) (Pt(0)/TPA@rGO NPs) are used as a stable, isolable, bottleable, long-lived, highly efficient and exceptionally reusable heterogeneous catalyst for eco-friendly hydrogenation of various aromatic aldehyde compounds with unprecendented catalytic performance. Pt(0)/TPA@rGO NPs have been used for the first time for these types of synthesis reactions and these NPs were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Herein, the catalyst has been used for tandem dehydrogenation of dimethylamine-borane (DMAB) and hydrogenation of aromatic aldehyde compounds in aqueous methanol at room temperature in reaction times ranging from 1.0 to 25 min with yields reaching up to 95%. The presented catalytic methodology is highly efficient as well as having exceptional reusability performance. This process can be assessed as an eco-friendly method with both a reusable reduced GO-supported platinum nanocatalyst and a hydrogen source (DMAB).

Recyclable aluminium oxy-hydroxide supported Pd nanoparticles for selective hydrogenation of nitro compounds via sodium borohydride hydrolysis

The reduction of aromatic/aliphatic nitro compounds to primary amines with high yields was easily realized by transfer hydrogenation comprising commercially available aluminium oxy-hydroxide-supported Pd nanoparticles (0.5 wt% Pd, Pd/AlO(OH)) as catalysts and NaBH4 as the hydrogen reservoir at room temperature in a water/methanol mixture (v/v = 7/3). The presented catalytic methodology is highly efficient for the reduction of various nitro compounds as well as reusable. A variety of R-NO2 derivatives were tested by performing the Pd/AlO(OH) catalysed reduction reaction and all the nitro compounds were selectively reduced to their corresponding primary amines in reaction times ranging from 0.75 to 13 min with yields reaching up to 99%. This process can be assessed as an eco-friendly method involving both reusable catalysts (Pd/AlO(OH) NPs) and hydrogen sources (NaBH4).

The inhibition effect of mad Honey on corrosion of 2007-type aluminium alloy in 3.5% NaCl solution

The inhibition effect of mad honey on corrosion of 2007-type aluminium alloy in 3.5% NaCl solution was investigated by Tafel extrapolarisation (TP), electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS). All the studied parameters exhibited good anti-corrosive properties against corrosion of 2007-type aluminium alloy in the test solution; the corrosion rates decreased with the increase of the mad honey concentration. The surface morphology of the alloy was examined under scanning electron microscopy (SEM) in the absence and presence of the inhibitor. The inhibitory adsorption processes of mad honey on the 2007-type aluminium alloy surfaces conformed to the Langmuir adsorption isotherm.

Selectivity and activity in catalytic hydrogenation of azido groups over Pd nanoparticles on aluminum oxy-hydroxide

Azidoarenes involving various functional groups were successfully reduced to aniline derivatives using commercially available aluminium oxy-hydroxide-supported palladium (Pd/AlO(OH)) nanoparticles (0.5 wt% Pd) in an aqueous medium with sodium borohydride as the hydrogen source. To develop the green process, water was utilized in conjunction with methanol. The results demonstrated that the halogen substituted azidoarenes were selectively converted to the corresponding aniline compounds without dehalogenation. In general, all of the reactions were completed within 10–30 min at room temperature with yields of over 99%. In order to optimize the reaction conditions, the parametric effects of the solvent type and the amount of the catalyst/NaBH4 were examined. Consequently, for the first time, a novel, practical and environmentally friendly process was developed for the conversion of azidoarenes to aniline derivatives in the fluence of Pd/AlO(OH) nanoparticles.