Conversion of toxic, indoor pollutants into innocuous products through catalytic reaction is one of the promising among other permanent solutions. γ-Al2O3 supported, Pt-based intermetallic nanoparticles (NPs) using abundantly available metal e.g., Fe (Pt-Fe; Pt3Fe and PtFe3) as catalysts are successfully prepared through a wet-impregnation method followed by calcination in the presence of H2 at 800 °C. Although the intermetallic Pt-Fe NPs are prepared at elevated temperatures, they are, however, not agglomerated and are finely dispersed on the γ-Al2O3 support with the average particle size between 4 and 6 nm. No other intermetallic or alloy phases of Pt-Fe were not observed under the set synthesis conditions. Despite the same Pt-mass loading in the both Pt-Fe catalysts, intermetallic PtFe3 catalysts showed much improved carbon monoxide (CO) oxidation activity by at least 8-fold compared to that of the intermetallic Pt3Fe catalysts. The intermetallic PtFe3 catalysts showed the enhanced activity for CO oxidation compared to that of the intermetallic Pt3Fe catalysts, however, both the intermetallic Pt-Fe catalysts showed virtually the same catalytic activity for benzene oxidation. Both the intermetallic Pt-Fe catalysts showed the stable, multi-cycle catalytic performance for the catalytic CO and benzene oxidation and retain their structure and morphology even after catalytic reaction.