Manganese carbonyl complexes for CO₂ reduction

The use of fossil fuels will continue to dominate the energy market for the next several decades. To mitigate the large amounts of CO₂ released into the atmosphere, it is essential to have clean ways of converting the CO₂ back into a high energy density liquid fuel. While still an emerging field, manganese-based catalysts can be successfully integrated into electrochemical and photoelectrochemical devices for CO₂ reduction. This review describes the design, feature and efficiency of manganese carbonyl systems reported in literature, for both electro- and photoreduction of CO₂. The spectroelectrochemical and spectroscopic techniques used to elucidate the associated catalytic mechanisms and reaction intermediates are also described. The evolution of the reported complexes highlights how progress is being made to eliminate the deficiencies of the early versions of these complexes, and how the future looks bright for their effective use in CO₂ reduction.