A spin-polarized density functional study has been performed to evaluate the favorability of reduction of N 2 O by oxidation of CO using pristine and doped molybdenum phosphide (MoP) as a catalytic surface. The stepwise mechanism, which comprises 4 steps, N 2 O dissociation (the rate-determining step), N 2 desorption, CO oxidation, and CO 2 desorption, has been explored in detail. Adsorption energy, charge transfer, relative energy, energy band structure, and projected density of states plots offer deeper insights into the simultaneous reduction and oxidation of N 2 O and CO, respectively. Four 3d transition metals have been considered for doping the MoP surface to further improve its catalytic performance. The energy barriers of N 2 O dissociation and CO oxidation over pristine and Cr-doped MoP surfaces have been evaluated and compared to those of previously reported catalysts. The activation of the N 2 O molecule that facilitates the breaking of the N−O bond is identified as the rate-determining step. Low desorption energy for the removal of the final products (N 2 and CO 2 ) ensures easy regeneration of the catalyst surface. The study offers ample evidence to exploit the Cr-doped MoP surface for simultaneous abatement of harmful N 2 O and CO gases by their respective conversion into N 2 and CO 2 .