A novel combustion synthesis of ceramic powder has been developed using humic acids (HA) as the complexible fuel. Synthesis of mixed oxide (Sm0.5Sr0.5CoO3 (SSC)) ceramic nanoparticles was chosen to illustrate synthetic procedures. SSC nanoparticles obtained by combustion of HA-metal complexes exhibited particle sizes of 50-100 nm, and good electrochemical performance as the cathode material for solid oxide fuel cells. The process of using renewable HA as the complexible fuel is of low cost, and thus suitable for sustainable production of various oxide ceramic materials.