Entry Date:
October 25, 2018

Earth-Abundant Catalysts for Oxygen Reduction

Principal Investigator Yogesh Surendranath


The four-electron, four-proton reduction of molecular oxygen to water is the efficiency limiting reaction in low-temperature fuel cells. Currently, expensive and scarce platinum-based catalysts are required to carry out this reaction, impeding widespread deployment of fuel cell technologies for automotive and portable power applications. We have developed a variety of low-cost earth-abundant transition metal-sulfide-based catalysts for this reaction. In particular, we have identified the haezlewoodite phase of nickel sulfide, Ni3S2 as a potent catalyst for oxygen reduction in benign neutral pH electrolytes (left). These metal sulfide catalysts are selective for oxygen reduction even in the presence of common fuels and resist poisoning by common electrolyte ions, making them particularly attractive or membrane-free mix-reactant fuels cell technologies. We are currently investigating the mechanisms of oxygen reduction catalysis by these materials and using these insights to develop improved catalysts that retain high selectivity.

Hypothesis-driven synthesis and rigorous physical characterization provide the basis for catalyst discovery and optimization. Students and postdoctoral scholars gain expertise in modern methods for the synthesis of inorganic coordination compounds, thin films, nanocrystals, and organic ligands. We employ a range of characterization tools including TEM, SEM, AFM, XPS, UV-Vis, IR, NMR etc. with a particular emphasis on electrochemical methods. These tools allow us to probe structure-function relationships that guide the development of new synthetic strategies.