Rachida Ghailane

Platinum is the most active pure metal for dehydrogenating methanol to create hydrogen, which is crucial for fuel cells. However, one significant disadvantage that reduces the effectiveness and long-term performance of platinum catalysts is their susceptibility to CO poisoning. In the current study, we examine and elucidate the promotional impact of Ge on Pt catalysts with increased resistance to deactivation by CO poisoning. We do this by combining partial density of states calculations with electronic configuration and Mulliken atomic charges. The self-consistent periodic density functional theory with dispersion correction (DFT-D) was used to investigate the methanol adsorption and dehydrogenation mechanisms on the surface of PtGe (110). On the surface, several adsorption mechanisms of pertinent intermediates were found. Furthermore, a thorough analysis of a reaction network comprising four reaction paths revealed that, in terms of activation barriers, the first O—H bond scission of CH3OH appears to be more advantageous than C—H bond cleavage on the PtGe(110) surface. Additionally, it has been demonstrated that the main route on the PtGe(110) surface is CH3OH→CH3O→CH2O→CHO→CO evolution. The remarkable differences in the predominant reaction pathway on the Pt(110) surface, and PtGe(110) surface indicate that the Ge-doped Pt Nano catalyst is more selective and resistant to deactivation.

The synthesis of quinoxaline derivatives were heterogeneously catalyzed by phosphate-based catalyst fertilizers, MAP, DAP, or TSP. The reaction affords the desired products in excellent yields at ambient temperature. A series of studies were conducted to investigate the effect of solvent reaction, its volume, and catalyst amount. A study of the recyclability of catalysts removed from the reaction mixture by simple filtration was also carried out to find that the three phosphate-based catalysts retain their catalytic activities up to six cycles.

This study presents a simple, efficient, and ecological procedure for the synthesis of biscoumarins and 3,4-dihydropyrano[c]chromenes under green conditions using Zn₃(PO₄)₂.4H₂O as a heterogeneous catalyst. In fact, Zn₃(PO₄)₂.4H₂O was prepared for the first time from triple superphosphate fertilizer (TSP) (Ca(H₂PO₄)₂) and zinc sulfate (ZnSO₄). Then, it was characterized by spectroscopic and microscopic technics such as X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The synthesis derivatives of biscoumarins and dihydropyrano[c]chromenes, in the optimal reaction conditions (nature of the solvent, amount of catalyst and temperature), was performed. The obtained results are excellent in terms of time (15–30 min) and yields (81–87%). Besides, Zn₃(PO₄)_2.4H₂O can be reused at least six times without significant loss of its catalytic activity, because of its long-term durability.

The aim of this work is to prove the efficiency of the Phosphate fertilizers mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and triple-super phosphate (TSP) as a “green” heterogeneous catalysts for the synthesis of 2-aryl-2H-benzo[b][1,4]thiazin-3(4H)-ones via the C-S and C-N coupling process of gem-dicyano epoxide with α-aminothiophenol. To optimize the reaction conditions, the synthesis was conducted with a range of solvents, catalyst amounts and catalyst particle sizes. Also, the potential recyclability of the catalysts was confirmed by running the reaction using the recycled catalyst.

A new strategy has been proposed for the synthesis of 9-arylhexahydroacridine-1,8-diones by three-component condensation of aromatic aldehydes with 5,5-dimethylcyclohexane-1,3-dione and ammonium...

This work presents a simple process for the preparation of Cobalt Orthophosphate (Co ₃ (PO ₄ ) ₂ ), by modifying phosphate fertilizer mono‐ammonium phosphate (MAP) by cobalt nitrate (Co(NO ₃ ) ₂ ). Co ₃ (PO ₄ ) ₂ has been characterised using microscopic and spectroscopic methods namely X‐ray diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM). It is the first time that Co ₃ (PO ₄ ) ₂ is used as a heterogeneous catalyst in the condensation between an aryl aldehyde, 4‐hydroxycoumarin and malononitrile. The results show that Co ₃ (PO ₄ ) ₂ is an effective catalyst for one‐pot synthesis of 3,4‐dihydropyrano [3, 2‐c] chromene. The optimisation of each reaction parameter allows achieving excellent results in terms of time and yield. The application of Co ₃ (PO ₄ ) ₂ as catalyst in the 3, 4‐dihydropyrano [3, 2‐c] chromene derivatives synthesis offers certain advantages such as shorter reaction time, simple treatment, furthermore, the catalyst possesses a great capacity for reutilization and therefore its application contributes to the development of green chemistry.

The present work focused on developing a new protocol of the 1-(benzothiazolylamino) methyl-2-naphthol derivatives synthesis by condensation of three compounds, i.e. aromatic 2-naphthol, 2-aminobenzothiazole and aldehyde. Furthermore, this reaction was carried out in the presence of three heterogeneous phosphate catalysts: monoammonium phosphates (MAP), diammonium phosphate (DAP), and trisuperphosphate (TSP). Moreover, this method offered many advantages, such as: very high yields, shorter reaction times, and the catalysts, can be easily recovered and reused without any loss of their catalytic activities.