A perspective on the electrocatalytic conversion of carbon dioxide to methanol with metallomacrocyclic catalysts

Abstract

Electrocatalytic carbon dioxide reduction (CO2R) presents a promising route to establish zero-emission carbon cycle and store intermittent renewable energy into chemical fuels for steady energy supply. Methanol is an ideal energy carrier as alternative fuels and one of the most important commodity chemicals. Nevertheless, methanol is currently mainly produced from fossil-based syngas, the production of which yields tremendous carbon emission globally. Direct CO2R towards methanol poses great potential to shift the paradigm of methanol production. In this perspective, we focus our discussions on producing methanol from electrochemical CO2R, using metallomacrocyclic molecules as the model catalysts. We discuss the motivation of having methanol as the sole CO2R product, the documented application of metallomacrocyclic catalysts for CO2R, and recent advance in catalyzing CO2 to methanol with cobalt phthalocyanine-based catalysts. We attempt to understand the key factors in determining the activity, selectivity, and stability of electrocatalytic CO2-to-methanol conversion, and to draw mechanistic insights from existing observations. Finally, we identify the challenges hindering methanol electrosynthesis directly from CO2 and some intriguing directions worthy of further investigation and exploration.