Highly Active and Durable Extended Surface Electrocatalysts

Highly Active and Durable Extended Surface Electrocatalysts

Shaun M. Alia, Staff Scientist, Chemical and Materials Sciences Center, National Renewable Energy Laboratory

Research Interests:

In the near future, fuel cell vehicles will become cost competitive with other drive train and fuel platforms. The commercial impact of proton exchange membrane fuel cells (PEMFCs), however, is still limited in part by catalyst cost, where the catalyst layer accounts for roughly half of fuel cell costs. Although platinum nanoparticles are commonly used due to high surface area and moderate activity, a reduction in catalyst loading or cost can improve PEMFC prospects and potentially accelerate its progress as a commercial product. In addition to catalyst cost, concerns have arisen due to the durability of the catalyst type.

Extended thin films have been studied as oxygen reduction catalysts since extended platinum surfaces generally offer site-specific activities an order of magnitude greater than nanoparticles. Extended nanostructures also avoid carbon as a support and may offer a long-term durability benefit. The catalyst type, however, has traditionally been limited by low surface area (10‒20 m² g^‒1), and improvements are typically accomplished through an alloying effect improving site-specific activity. In this talk, progress in developing PEMFC catalysts through various deposition techniques will be presented. This work includes platinum-nickel nanowires, which have surface areas in excess of 90 m² g^‒1 and mass activities an order of magnitude greater than platinum nanoparticles in half-cell testing.

Recently, aspects of fuel cell catalyst development have been applied to hydrogen-producing electrolysis technologies. Although the cost of electrolyzers is currently dominated by feedstock costs, capital and catalyst costs will become increasingly vital as the power input shifts to renewable, intermittent sources of energy. Advancement in water splitting will be presented, including the development of extended iridium nanostructures in the oxygen evolution reaction. In cases, these materials produce activities an order of magnitude greater than commercial nanoparticles while offering a potentially significant durability advantage.

Teaching Interests:

My research is in electrochemistry and the development of nanomaterials for energy applications and my teaching experience was attained in chemistry and chemical engineering departments. The breadth of my experiences has provided preparation for teaching a variety of courses. While I am capable of teaching any course in the core curriculum, I am particularly interested in teaching kinetics and transport. Teaching undergraduate or graduate electives is also an interest, on areas aligned with my research, including electrochemistry as it relates to catalyst development. The inclusion of courses related to electrochemistry can inspire students to contribute to the advancement of the field and embraces the spirit of chemical engineering, an ever-evolving discipline at the forefront of technological advancement.

In previous experience as a teaching assistant, I emphasized student participation by having them periodically instruct each other. By running discussion sections and being a guest lecturer, experience was also attained in the practical aspects of teaching, including preparing lectures, lesson plans, and exams. As a faculty candidate, I am interested in promoting student involvement and providing practical applications to support concepts in the form of video or demonstrations. In addition to teaching core chemical engineering courses, I also am interested in bringing energy and nanomaterial related courses into the curriculum.