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Solar-driven CO2 reduction to yield high-value chemicals presents an appealing avenue for combating climate change, yet achieving selective production of specific products remains a significant challenge. We showcase two osmium complexes, przpOs, and trzpOs, as CO2 reduction catalysts for selective CO2-to-methane conversion. Kinetically, the przpOs and trzpOs exhibit high CO2 reduction catalytic rate constants of 0.544 and 6.41 s−1, respectively. Under AM1.5 G irradiation, the optimal Si/TiO2/trzpOs have CH4 as the main product and >90% Faradaic efficiency, reaching −14.11 mA cm−2 photocurrent density at 0.0 VRHE. Density functional theory calculations reveal that the N atoms on the bipyrazole and triazole ligands effectively stabilize the CO2-adduct intermediates, which tend to be further hydrogenated to produce CH4, leading to their ultrahigh CO2-to-CH4 selectivity. These results are comparable to cutting-edge Si-based photocathodes for CO2 reduction, revealing a vast research potential in employing molecular catalysts for the photoelectrochemical conversion of CO2 to methane. Solar-driven CO2 conversion to produce solar fuels is an attractive way to harness solar energy and reduce carbon emissions. Here, the authors report two osmium complexes as highly active and selective CO2 reduction catalysts for selective CO2-to-methane conversion on Si-based photocathodes. [ABSTRACT FROM AUTHOR]

For four decades, cordgrass (Spartina alterniflora) has invaded salt marshes in the Yellow Sea, altering physical, biogeochemical, and biological processes. Here, we investigated the ecological effects of S. alterniflora invasion on benthic environments compared to native halophytes. S. alterniflora contributed to higher carbon accumulation rates compared with bare tidal flat in sediments (3.4 times), through greater primary production and root biomass, compared to Suaeda japonica (2.5 times) and Phragmites australis (2.4 times) over the given period. The results showed that S. alterniflora eradication treatments inhibited its growth but did not significantly affect the benthic communities. Compared to P. australis and bare tidal flats, S. alterniflora invasion resulted in lower greenhouse gas emission and higher contributions to macrobenthos nutrition, and increased sediment stability and carbon burial. Overall, these multiple lines of evidence provide new insights on S. alterniflora invasion, suggesting that the current eradication policy would be carefully reviewed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Solar-driven CO 2 reduction to yield high-value chemicals presents an appealing avenue for combating climate change, yet achieving selective production of specific products remains a significant challenge. We showcase two osmium complexes, przpOs, and trzpOs, as CO 2 reduction catalysts for selective CO 2 -to-methane conversion. Kinetically, the przpOs and trzpOs exhibit high CO 2 reduction catalytic rate constants of 0.544 and 6.41 s -1 , respectively. Under AM1.5 G irradiation, the optimal Si/TiO 2 /trzpOs have CH 4 as the main product and >90% Faradaic efficiency, reaching -14.11 mA cm -2 photocurrent density at 0.0 V RHE . Density functional theory calculations reveal that the N atoms on the bipyrazole and triazole ligands effectively stabilize the CO 2 -adduct intermediates, which tend to be further hydrogenated to produce CH 4 , leading to their ultrahigh CO 2 -to-CH 4 selectivity. These results are comparable to cutting-edge Si-based photocathodes for CO 2 reduction, revealing a vast research potential in employing molecular catalysts for the photoelectrochemical conversion of CO 2 to methane., (© 2024. The Author(s).)