Carbon Nanohorn Support for Solar driven CO2 Reduction to CO Catalyzed by Mn-complex in an All Earth-abundant System

An Mn-complex supported on multi-walled carbon nanotubes (MWCNTs) has been reported to be a superior catalyst for CO2 reduction to CO, where the carbon support strongly influences the catalytic activity, enabling operation at a low overpotential. Here, the effects of various carbon supports on the activity of a Mn-complex catalyst were investigated. Among the various carbon supports, which included carbon black and MWCNTs, carbon nanohorns (CNHs) were the best support for enhancing the catalytic activity of the Mn-complex toward CO2 reduction. This enhancement was attributed to the CNHs' high specific surface area and hydrophobic nature. For solar-driven CO2 reduction to CO, the Mn-complex catalyst supported on CNHs was series-connected to Ni-doped beta-FeOOH as a water oxidation catalyst via a Si solar cell; a solar-to-CO conversion efficiency of 3.3 +/- 0.4% was achieved in a single-compartment reactor.

Automated summary

Carbon nanohorns (CNHs) have been found to be the best support material for Mn-complex catalyst in CO2 reduction to CO, due to their high specific surface area and hydrophobic nature.