Nitrogen-functionalized platinum-iridium electrocatalyst
The invention provides a nitrogen-functionalized platinum-transition metal catalyst having the formula Pt-M-N X /C (where M is a transition element such as Fe, Co, Ni, Nb, Ta, Ir, Rh, or Ru) for use at the hydrogen electrode of a hydrogen/bromine redox flow battery. The new catalyst possesses excellent activity and durability in the HBr/Br 2 environment, showing superior resistance to halide poisoning than conventional Pt/C or Pt-M/C catalysts.
1. A catalyst comprising metallic nanoparticles bound to a solid support, the metallic nanoparticles comprising a material having a formula of Pt-M-N X , wherein M is a transition metal element selected from the group consisting of Ir- and Rh, and wherein 0.1<x<10, wherein the solid support comprises carbon black nanoparticles or microparticles, and wherein the catalyst comprises 10% to 70% (wt/wt) of the material having a formula of Pt-M-N X .
2. The catalyst of claim 1 , wherein M is Ir.
3. The catalyst of claim 1 that is suitable for use as an electrocatalyst in a reversible hydrogen electrode of a hydrogen-bromine redox flow battery.
4. The catalyst of claim 1 that is more stable in a hydrogen-bromine redox flow battery than a Pt/C or Pt-M/C catalyst.
5. The catalyst of claim 4 that is more resistant to halide poisoning hydrogen-bromine redox flow battery than a Pt/C or Pt-M/C catalyst.
6. An electrode comprising the catalyst of claim 1 .
7. A proton exchange membrane electrolyzer comprising the catalyst of claim 1 .
8. A hydrogen-bromine redox flow battery comprising the catalyst of claim 1 .
9. A method of making a hydrogen-bromine redox flow battery, the method comprising adding the catalyst of claim 1 to a structure as part of a process to produce a hydrogen-bromine redox flow battery.