Most of the reported bromination methods are based on using liquid bromine, but Liquid bromine is a hazardous and toxic reagent. Therefore, different approaches have been proposed for bromination in the absence of this reagent. We have used the oxidative bromination in this research. We have studied bromination of the ?-ketoester and 1,3-dicarbonyl compounds in a triphasic condition in the presence of Mg-Al-CO 3 2- -LDH and Br 3 - ,which was produced on the surface of LDH by oxidation of Br - ion with V 2 O 5 /H 2 O 2 or oxone. Different techniques such as XRD, FT-IR and UV-vis spectrophotometry were used for characterization of the catalysts. In order to enhance the yield, reaction conditions such as temperature, time, amount of oxidant and Mg-Al-CO 3 2- -LDH were optimized. In the second part of this research, preparation of ZrO 2 -TiO 2 mix oxides with molar ratio ‌Zr/Ti =1 was carried out and modification of the catalytic properties of these compounds was accomplished with different amounts of phosphoric acid in the presence and absence of surfactant. The acidic properties of the H 3 PO 4 /ZrO 2 -TiO 2 mixed oxides were characterized through pyridine absorption-desorption method. The nitration of phenol was carried out in the presence of nitric acid, in liquid phase, over the prepared catalysts. The results indicated that this new procedure ends up to a high selectivity for producing 2-nitrophenol and high conversion of phenol via this catalyst was obtained. Different conditions (temperature, time, ratio of materials, solvent and etc) were optimized and the appropriate catalyst was selected.