Catalytic Nanoparticle Modifiers for Biodiesel-Diesel Blends: Performance Recovery, Emission Suppression, and Stability Constraints

Abstract

Sustainable liquid fuels are vital for decarbonizing compression-ignition engines in transport, agriculture, marine power, and decentralized energy systems. Biodiesel is renewable and oxygenated, but its lower heating value, higher viscosity, increased fuel consumption, and variable NOx emissions limit wider use. This review examines nanoparticle-enhanced biodiesel blends as sustainable fuel systems for improving combustion and emissions. A Scopus-based corpus from 2017–2026 was screened, yielding 74 studies, each classified by nanoparticle type, feedstock, engine platform, co-additive strategy, response domain, and optimal dosage. Al₂O₃, TiO₂, and CeO₂ are the most studied additives, while graphene, carbon nanostructures, CuO, ZnO, and iron-based particles are emerging.