Photoelectrochemical conversion of CO2 to methanol.
01/03/2021 - 28/02/2025
The increasing anthropogenic emissions of greenhouse gases into the Earth’s atmosphere has caused a deterioration of natural phenomena over the past few years. CO2 is the main component causing this global effect, called climate change. For tackling this effect, new solutions, such as carbon capture and utilization(CCU), are crucial to close the carbon cycle. A (photo-)electrochemical mechanism using sunlight and renewable energy is a sustainable and green CCU technique for converting CO2 to energetic molecules such as methanol.
The state-of-the-art synthesis for methanol has derived from syngas, a mixture of CO and H2, usually obtained from coal and natural gas. Additional applications of this molecule include a chemical building block and fuel storage, ideal for storing intermitting energy of the power grid. Therefore, the combination of a green, sustainable (photo-)electrochemical mechanism and the broad market makes methanol a compelling product.
However, the electrochemical reduction of CO2 towards methanol is not an easy task due to the nature of the reaction (six-electrons/protons coupling), sluggish kinetic and competing reactions (Hydrogen Evolution Reaction, CO or HCOOH formation) that lower the selectivity/Faradaic efficiency. Nevertheless, the photochemical reduction shows high selectivity towards methanol, but the production rates are low. Combining the photochemical and electrochemical mechanism can lead to a promising result for the production of methanol.