Carbon-supported copper manganite nanoparticles for biofuel production

A method of preparing nanoparticles of carbon-supported copper manganite (CuMn2O4), the method comprising:

• preparing a first solution of a copper (II) salt and a manganese salt in a first polar organic solvent, wherein the molar ratio of Cu:Mn is from about 0.8:1 to about 1.2:1;
• admixing a second solution of an organic ligand in a second polar organic solvent with the first solution to form a first mixture, wherein the second polar organic solvent is miscible with said first polar organic solvent;
• hydrothermally heating the first mixture at a temperature of from about 100° C. to about 200° C. for a sufficient duration to form a solid metal-organic framework composite material;
• and,
• calcining said metal-organic framework composite material at a temperature of from about 350 to about 600° C.,
• wherein the copper manganite (CuMn2O4) of the nanoparticles has a crystalline spinel lattice which comprises copper in each of the Cu+ and Cu2+ oxidation states and comprises manganese in each of the Mn3+ and Mn4+ oxidation states;
• and,
• further wherein a fraction of the nanoparticles have a core-shell morphology in which a shell of elemental carbon at least partially encapsulates a core nanoparticle of copper manganite (CuMn2O4).