Non-carbon mixed-metal oxide electrocatalysts
Electrocatalysts having non-corrosive, non-carbon support particles are provided as well as the method of making the electrocatalysts and the non-corrosive, non-carbon support particles. Embodiments of the non-corrosive, non-carbon support particle consists essentially of titanium dioxide and ruthenium dioxide. The electrocatalyst can be used in fuel cells, for example.
1. A method of preparing an electrocatalyst comprising: preparing non-carbon composite support particles comprising:
oxidizing ruthenium nanoparticles to obtain ruthenium dioxide nanoparticles; and
reducing a titanium precursor and depositing titanium nanoparticles onto the ruthenium dioxide nanoparticles in a liquid, wherein each of the ruthenium dioxide nanoparticles has a first particle size and each of the titanium nanoparticles has a second particle size, the first particle size being greater than the second particle size, wherein the first particle size is greater than 10 and less than or equal to 40 nanometers and the second particle size is greater than or equal to 5 and 10 nanometers;
agglomerating titanium nanoparticles to produce agglomerated titanium particles with a particle size that is the same as the first particle size deposited on the ruthenium dioxide nanoparticles; and
oxidizing the agglomerated titanium particles to form titanium oxide nanoparticles; and depositing active catalyst particles on the non-carbon composite support particles.
2. The method of claim 1 , wherein the active catalyst particles are a platinum alloy deposited onto each non-carbon composite support particle.
3. The method of claim 1 , wherein the active catalyst particles are platinum nanoparticles deposited onto each non-carbon composite support particle, each of the platinum nanoparticles having a diameter between 3 nm and 6 nm.
4. The method of claim 1 , further comprising:
prior to depositing the active catalyst particles, modifying a surface of the non-carbon composite support particles with a chemical process configured to promote adhesion of the active catalyst particles.
5. The method of claim 4 , wherein the modified surface of each non-carbon composite support particle comprises one or more of defects and functional groups configured to promote adhesion of the active catalyst particles.
6. The method of claim 5 , wherein the active catalyst particles are deposited onto the one or more of defects and functional groups.
7. The method of claim 1 , wherein the active catalyst particles are a multi-layer core shell deposited onto each non-carbon composite support particle.
8. The method of claim 1 , wherein the titanium oxide nanoparticles are a modified titanium dioxide, the method further comprising, prior to depositing and after reducing to the titanium oxide nanoparticles are:
mixing a dopant with a titanium dioxide precursor; and
reacting the mixture to form the modified titanium dioxide.
9. The method of claim 8 , wherein the dopant is one of both of niobium and tantalum.