(293c) Platinum Group Metal-Free Catalysts for Electrochemical Energy Conversion

Platinum group metal-free (PGM-free) electrocatalysts represent a low-cost alternative to their precious-metal-based counterparts for several reactions of fundamental importance to electrochemical energy conversion and storage. Of various proposed PGM-free catalysts, the atomically dispersed transition metal-nitrogen-carbon (M-N-C) materials have been found to be especially promising for oxygen reduction reaction (ORR) as potential replacement for Pt-based cathode catalysts in low-temperature polymer electrolyte fuel cells (PEFCs). More recently, these catalysts have shown respectable activity for electrochemical reduction of carbon dioxide (CO₂RR). PGM-free catalysts have also been developed for low-temperature water electrolyzers (LTWEs) operating with anion exchange membranes. Examples of catalysts for oxygen evolution reaction for the LTWE anode include Ni alloys (typically involving another transition metal) and a variety of oxides, e.g., perovskites. Ni alloys are also commonly used as hydrogen evolution reaction (HER) catalysts at the LTWE cathode.

In this presentation, we will review recent progress in the development of PGM-free catalysts for several electrochemical reactions of high importance to energy conversion: ORR in PEFCs, OER and HER catalysts in LTWEs utilizing anion exchange membranes, and CO₂RR in electrolyzers designed for the conversion of CO₂ to various value-added products. This presentation will specially focus on the activity and performance durability of electrocatalysts for these reactions.