Mechanism Construction and Combustion Characteristics Analysis of Diesel Fuel Blended with Nano-CeO 2

Abstract The catalytic influence of CeO 2 nanoparticles on diesel combustion was investigated through detailed kinetic modeling. A diesel surrogate consisting of n - dodecane ( NC 12 H 26 ) and p-xylene ( C 8 H 10 ) was adopted to represent the major chemical characteristics of real diesel fuel. A catalytic reaction mechanism describing the redox behavior of cerium dioxide ( CeO 2 ) was incorporated into the base fuel mechanism to construct a simplified kinetic framework for CeO 2 nanofuels. Combustion simulations were performed under various initial temperatures and pressures to evaluate the influence of CeO 2 nanoparticles on ignition behavior and combustion reactivity. The results indicate that the addition of CeO 2 significantly promotes the formation of OH and H 2 O 2 radicals at relatively low temperatures, leading to shorter ignition delay and enhanced heat release rates. At higher temperatures, combustion is dominated by rapid thermal decomposition of fuel molecules, which reduces the dependence of the system on catalytic radical generation and weakens the catalytic influence of CeO 2 . Furthermore, CeO 2 nanoparticles accelerate hydrocarbon oxidation and CO conversion while also enhancing nitrogen oxides ( NO x ) reduction reactions. Reaction pathway analysis shows that the primary oxidation pathways of the base fuel remain unchanged, whereas the catalytic reactions mainly affect radical formation and intermediate oxidation processes. These findings provide insight into the catalytic combustion mechanism of CeO 2 nanofuels and their potential for improving diesel combustion performance.