ABSTRACT The synthesis of carbonated hydrocalumites could be troublesome because the carbonate anions can precipitate as calcium carbonate, therefore the aging times should be reduced. In this paper, carbonated hydrocalumites were synthesized using an unique gel divided in two portions: a part was aging to temperature room for 30 min, and the other one, by microwave radiations for 2 min. Samples were characterized by different techniques such as: Fourier-transformed infrared spectroscopy, X-ray diffraction, BET surface measurements, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Then, they were tested as antacid using a synthetic gastric juice. Results showed that carbonated hydrocalumites aging by microwave radiations were more flawless than those obtained by the conventional method. Moreover, using microwave radiations, the aging times were notably reduced and the purity of carbonated hydrocalumites was improved. The antacid properties were similar for hydrocalumites synthesized by different ways. However, they showed they showed better antacid properties with higher antacid capacity than commercial antacid.

A hydrocalumite-type material (HC) was synthesized by the co-precipitation method, mixing Ca and Al nitrate solutions in a NaOH solution (pH ≅ 11). This solid was characterized by using different physico-chemical techniques such as: Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), temperature programmed reduction (TPR) and BET surface area measurements. Then, a portion of as-synthesized solid was calcined at 420 ºC (HC 420). Both calcined and pristine solids were impregnated with Mo (15% w/w as MoO3). Ni or Co was also impregnated on Mo/HC or Mo/HC 420 in 1(Co or Ni):3 (Mo) atomic ratios to get catalytic precursors. These solids were also characterized by the above mentioned techniques. Catalytic precursors were tested in the thiophene hydrodesulfuration reaction at 280 ºC and atmospheric pressure. Cobalt promoted catalysts were more active than those promoted with Ni. However, thiophene conversions were lower than that of a conventional CoMo/γ-Al2O3 catalyst.