Halloysite-based nanocomposites and methods of making and using the same

A transition metal catalyst system comprising:

• a halloysite-based nanocomposite, the nanocomposite comprising transition metal nanoparticles embedded upon the internal surface of a halloysite nanotube wherein the transition metal comprises copper (Cu), palladium (Pd), Iridium (Ir) or rhodium (Rh), and wherein the size of the nanoparticles is less than 25 nm;
• a solvent, a base, and a capping agent,
• wherein the solvent comprises water, wherein the capping agent comprises a water soluble chemical,
• wherein the halloysite nanotube comprises a hydrated structure,
• and wherein the capping agent is operable to form the transition metal nanoparticles in an aqueous solution and prevent agglomeration.