Publications by authors named "Shanna Knights"

Exploring inexpensive and high-performance nonprecious metal catalysts (NPMCs) to replace the rare and expensive Pt-based catalyst for the oxygen reduction reaction (ORR) is crucial for future low-temperature fuel cell devices. Herein, we developed a new type of highly efficient 3D porous Fe/N/C electrocatalyst through a simple pyrolysis approach. Our systematic study revealed that the pyrolysis temperature, the surface area, and the Fe content in the catalysts largely affect the ORR performance of the Fe/N/C catalysts, and the optimized parameters have been identified.

View Article and Find Full Text PDF

Direct growth of multigrain platinum nanowires on sulfur-doped graphene (PtNW/SG) is reported. The growth mechanism, including Pt nanoparticle nucleation on SG, followed by nanoparticle attachment with orientation along the <111> direction is highlighted. PtNW/SG demonstrates improved Pt mass and specific activity compared with commercial catalysts toward oxygen reduction, in addition to dramatically improved stability through accelerated durability testing.

View Article and Find Full Text PDF

Encapsulation of Pt nanoparticles (NPs) in a zirconia nanocage by area-selective atomic layer deposition (ALD) can significantly enhance both the Pt stability and activity. Such encapsulated Pt NPs show 10 times more stability than commercial Pt/C catalysts and an oxygen reduction reaction (ORR) activity 6.4 times greater than that of Pt/C.

View Article and Find Full Text PDF