Solar-driven CO₂ to CO reduction utilizing H₂O as an electron donor by earth-abundant Mn–bipyridine complex and Ni-modified Fe-oxyhydroxide catalysts activated in a single-compartment reactor

Abstract

Solar-driven CO2 reduction utilizing earth-abundant catalysts of a Mn-complex and Ni-modified β-FeOOH was demonstrated in a single-compartment reactor.

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

“…Artificial photosynthesis for producing fuels or chemicals from CO 2 and H 2 O has also been developed as a CO 2 conversion method because it enables CO 2 to be converted to valuable substances and solar energy to be stored as chemical energy [2] . Electrocatalysts for CO 2 reduction have recently become an active research area because these electrocatalysts can be combined with solar‐cell systems [2d–l] . However, the development of such electrocatalysts still faces major problems.…”

“…The cathode surface area is typically larger than that of solar cells for solar‐driven CO 2 reduction with high solar conversion efficiency because the CO 2 reduction reaction is the rate‐limiting step in a CO 2 reduction system [2l] . Therefore, in a previous study, a cathode electrode with a surface area (3.24 cm 2 ) larger than that of the Si solar cell (1.6 cm 2 ) was used [2d] . The CNHs used in the present study enabled the utilization of a cathode electrode with a surface area (1.0 cm 2 ) smaller than that of a Si solar cell to achieve a solar‐to‐CO conversion efficiency almost as high as that of the previously reported device [2d] …”

“…Therefore, in a previous study, a cathode electrode with a surface area (3.24 cm 2 ) larger than that of the Si solar cell (1.6 cm 2 ) was used [2d] . The CNHs used in the present study enabled the utilization of a cathode electrode with a surface area (1.0 cm 2 ) smaller than that of a Si solar cell to achieve a solar‐to‐CO conversion efficiency almost as high as that of the previously reported device [2d] …”

“…MWCNTs have previously been used as a support material for [Mn−MeCN] catalysts for CO 2 reduction to CO [1g,2d] . To improve the catalytic activity of [Mn−MeCN] for CO 2 reduction, we investigated the effects of other carbon supports such as CNHs, graphene nanoplatelets (GNPs), carbon black (CB), and carbon nanofibers (CNFs).…”

“…In a previous study, solar‐driven CO 2 reduction was demonstrated using a [Mn−MeCN] supported on MWCNTs as a CO 2 reduction catalyst, Ni‐doped β‐FeOOH as a water oxidation catalyst, and a Si solar cell [2d] . The solar‐to‐CO conversion efficiency was ∼3.4% when a CP/MWCNT/[Mn−MeCN] electrode with an area of 3.24 cm 2 was used [2d] .…”