A novel organic ternary mixture composed of Lauric acid, Myristic acid, and Dodecanol (referred to as LMD) has been synthesized as a Phase Change Material (PCM), specifically designed for cold storage applications. Although organic PCMs are highly effective, their low thermal conductivity frequently restricts their heat transfer performance. To address this issue, a hybrid Nano-enhanced PCM (HNe-PCMs) has been developed in this study. This involved dispersing two types of nanoparticles, Graphene nanoparticles (GNP)-Al2O3 and GNP-CuO, each at a 1% weight fraction, within the LMD matrix. The thermal and chemical characteristics of developed pure LMD and HNe-PCMs were studied using electron microscope scanning (SEM), Fourier transform infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), thermal conductivity analyser (TC), Differential scanning calorimeter (DSC), and Thermo gravimetric analyser (TGA) and explored their potential in cold storage application. Chemical and thermal characterization revealed that the freezing and melting temperatures of LMD are 8.4 ± 0.1°C and 15.6 ± 0.1°C, respectively, with corresponding latent heats (LH) of freezing/melting of 125.4 ± 1.8 J/g and 131.5 ± 1.8 J/g. Upon incorporation of the nanoparticles, the thermal conductivities of LMD/GNP-Al2O3 and LMD/GNP-CuO were notably enhanced by 57.4% and 49.8%, respectively, compared to pure LMD. However, a slight deviation in the melting/freezing LH of 2.9% and 1.9%, and in phase change temperature of 12.1% and 7.1%, respectively, was observed for the LMD/GNP-Al2O3 HNe-PCMs compared to the pure LMD. Through effectiveness analysis, it was depicted that the LMD/GNP combined with Al2O3 exhibits a reduction of 13.94% and 12.4% in charging-discharge time compared to pure LMD. In contrast, the LMD/GNP with CuO showed a 12.73% and 10.87% reduction in these times respectively. Overall, LMD/GNP-Al2O3 emerges as a promising material for passive cold storage applications, improving thermal conductivity while preserving similar phase change characteristics to pure LMD performance.