Me-N-C Electrocatalysts for Electrochemical CO2 Reduction to High-Value Products

Abstract

The development of sustainable carbon-neutral energy technologies to mitigate greenhouse gas emissions has become imperative and urgent. Of special interest and importance in this context is the use of electricity from intermittent renewable energy sources (wind, solar) for electrochemical conversion of carbon dioxide (CO2) to easily storable and transportable value-added products: fuels and feedstock chemicals. Nanoparticles of non-precious metals, e.g., Cu, Sn, Co, show high activity for electrochemical CO2 reduction reaction (CO2RR) but suffer from poor selectivity, resulting in a mixture of products that require tedious and costly separation. Recently, transition metal- and nitrogen-doped carbon (Me-N-C) materials have been emerged as promising CO2RR catalysts thanks to their well-defined structures and good activity. However, their selectivity, while respectable for the generation of carbon monoxide (CO), is low for high energy-content products. A limited understanding of reaction pathways and degradation mechanism of Me-N-C catalysts for CO2RR has additionally stemmed a rational design of these materials.In this presentation, we summarize our study of the activity, selectivity, and stability of Me-N-C (Me = Fe, Co, Ni, or Cu, etc.) catalysts for the CO2RR, focusing on the role of the local coordination environment at metal centers and metal-carbon substrate interactions. We also report the obtained bimetallic M1M2-N-C catalysts, designed to enable the formation of multi-carbon products through CO2RR and utilizing high surface-area three-dimensional carbon matrix as support for metal sites with improved CO2RR activity. The main objective of this work is to use Me-N-C catalysts to produce high energy-density chemicals, enhance mechanistic understanding, and bring CO2RR closer to practical applications.