<p>This work examines magnetohydrodynamic (MHD) flow of a nanoliquid through on a porous surface. The mathematical model includes the collective effects of thermophoresis and Brownian motion to accurately describe nanoparticle behavior. It further analyzes the effect of Arrhenius activation energy on chemically reactive species. The flow is administrated by a convective heating condition, while the concentration field is subjected to a physically realistic zero mass flux condition. The bvp4c approach is used in this work to solve the modeled equations in dimension-free form. It is revealed as outcomes of this work that, for augmentation in magnetic factor, inter-particle spacing and porosity factor there is lessening in primary and secondary flows. Both the velocities augmented with progression in radius of nanoparticles. Thermal profiles augmented with growth in thermal Biot number, and magnetic factor while declined with augmentation in thermal relaxation time factor. Concentration panels augmented with progression in thermophoresis factor and activation energy factor while weakened with augmentation in Schmidt number and Brownian motion factor. A comparative analysis with established results confirms the accuracy and validity of the present model. The close agreement between our numerical outputs and the published data verifies the correctness of the solution methodology and the physical consistency of the formulated problem. This study demonstrates that the simultaneous adjustment of inter-particle spacing and nanoparticle size provides a strategic approach for enhancing thermal performance relative to pumping in nanofluid-based systems, with immediate ramifications for the design of advanced microelectronics coolants and magnetically guided delivery platforms.</p>