Hydrothermal transport of a chemically reactive bioconvective hybrid nanofluid with activation energy in MHD stagnation-point flow over a stretching surface

This study presents a detailed numerical investigation of MHD stagnation-point flow of a chemically reactive bioconvective hybrid nanofluid over a stretching surface, incorporating the coupled influences of Brownian diffusion, thermophoresis, viscous dissipation, heat generation/absorption, magnetic field, and activation energy. The hybrid nanofluid contains suspended nanoparticles whose transport is described via Buongiorno’s model, while motile microorganisms induce bioconvection in the boundary layer. A homogeneous first-order chemical reaction with Arrhenius-type activation energy is considered to capture nanoparticle consumption and temperature-dependent reaction kinetics relevant to catalytic and reactive transport systems. Using similarity transformations, the governing steady boundary-layer equations are reduced to a system of nonlinear ordinary differential equations and solved numerically via MATLAB’s bvp4c algorithm. The results reveal that stronger chemical reaction rates substantially suppress solute concentration within the boundary layer, whereas higher activation energy delays reaction onset and enhances nanoparticle retention. The combination of Brownian motion and thermophoresis enhances thermal and solutal diffusion rates which enable researchers to manage heat and mass transfer in reaction–diffusion hybrid nanofluid systems. The calculated skin friction and Nusselt and Sherwood numbers and motile microorganism density numbers demonstrate how hydrodynamic forces interact with thermal and solutal and bioconvective transport mechanisms. The research results have immediate value for chemical and process engineering because they support applications including catalytic surface cooling and bio-reactive coating flows and nanofluid-assisted separation processes and bioconvective transport in functional fluids. The research findings directly support chemical and process engineering applications because they enable better control of nanoparticle movement and chemical reactions and microorganism behavior in functional fluids.