Nitrogen oxides (NOx) emissions adversely impact the environment and human health. Necessary action is needed to control NOx emission from automotive exhausts. The three-way automotive catalytic converter is not effective for NOx reduction in an excess oxygen environment, encountered in diesel and lean-burn exhaust. Therefore, a new catalytic system is required for NOx reduction even in excess of oxygen. Such a system that uses hydrocarbon as reducing agent is known as hydrocarbon-based selective catalytic reduction (HC-SCR). Literature studies point towards the effectiveness of Ag based catalysts for HC-SCR. In this work, we use various techniques those are coprecipitation, impregnation and single step sol-gel methods to synthesize γ-Al2O3 supported Ag-based catalysts for NOx reduction using HC-SCR and these catalysts show promising results in terms of activity. There are physical and chemical changes of catalysts when changes in molar concentrations of HNO3 when it is added while preparing the sol-gel catalysts lead interest towards the study of the effect of the molar concentration of HNO3. With addition of lower molar concentration of HNO3 results into a better catalyst for NOx conversion into N2, and with good XRD patterns and higher surface area than the catalysts prepared at other HNO3 molar concentrations. To increase the activity of Ag/γ-Al2O3 catalyst in the lower temperature range, the addition of metal catalysts is needed for the better bi-metallic catalysts. The metal catalysts selected are: Bi, Mo, V, Rh and Pd in the preference order based on the literature search done. The packed bed reactor experiments will be done at near real lean-burn engine exhaust conditions such as at higher space velocities, at higher oxygen amounts into the feed gas and by varying the concentrations of reductant (propylene) into the reactor. Finally, microkinetic modelling will be done with selected optimized catalyst.