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Solar‐energy‐driven photoreduction of CO2 is promising in alleviating environment burden, but suffers from low efficiency and over‐reliance on sacrificial agents. Herein, rhenium (Re) is atomically dispersed in In2O3 to fabricate a 2Re‐In2O3 photocatalyst. In sacrificial‐agent‐free photoreduction of CO2 with H2O, 2Re‐In2O3 shows a long‐term stable efficiency which is enhanced by 3.5 times than that of pure In2O3 and is also higher than those on Au‐In2O3, Ag‐In2O3, Cu‐In2O3, Ir‐In2O3, Ru‐In2O3, Rh‐In2O3 and Pt‐In2O3 photocatalysts. Moreover, carbon‐based product of the photoreduction overturns from CO on pure In2O3 to CH3OH on 2Re‐In2O3. Re promotes charge separation, H2O dissociation and CO2 activation, thus enhancing photoreduction efficiency of CO2 on 2Re‐In2O3. During the photoreduction, CO is a key intermediate. CO prefers to desorption rather than hydrogenation on pure In2O3, as CO binds to pure In2O3 very weakly. Re strengthens the interaction of CO with 2Re‐In2O3 by 5.0 times, thus limiting CO desorption but enhancing CO hydrogenation to CH3OH. This could be the origin for photoreduction product overturn from CO on pure In2O3 to CH3OH on 2Re‐In2O3. The present work opens a new way to boost sacrificial‐agent‐free photoreduction of CO2. [ABSTRACT FROM AUTHOR]

The pressure dependent reaction mechanism of CO2 hydrogenation over In2O3 was investigated. CO2 hydrogenation on In2O3 can produce methanol only at high pressure, while the atmospheric pressure operation leads to the formation of CO. The conversion from HCOO* to H3CO* is accelerated at high pressure, leading to the formation of methanol with the formate route (CO2* → HCOO* → H3CO* → H3COH). [ABSTRACT FROM AUTHOR]

Summary: Grass lignocelluloses feature complex compositions and structures. In addition to the presence of conventional lignin units from monolignols, acylated monolignols and flavonoid tricin also incorporate into lignin polymer; moreover, hydroxycinnamates, particularly ferulate, cross‐link arabinoxylan chains with each other and/or with lignin polymers. These structural complexities make grass lignocellulosics difficult to optimize for effective agro‐industrial applications. In the present study, we assess the applications of two engineered monolignol 4‐O‐methyltransferases (MOMTs) in modifying rice lignocellulosic properties. Two MOMTs confer regiospecific para‐methylation of monolignols but with different catalytic preferences. The expression of MOMTs in rice resulted in differential but drastic suppression of lignin deposition, showing more than 50% decrease in guaiacyl lignin and up to an 90% reduction in syringyl lignin in transgenic lines. Moreover, the levels of arabinoxylan‐bound ferulate were reduced by up to 50%, and the levels of tricin in lignin fraction were also substantially reduced. Concomitantly, up to 11 μmol/g of the methanol‐extractable 4‐O‐methylated ferulic acid and 5–7 μmol/g 4‐O‐methylated sinapic acid were accumulated in MOMT transgenic lines. Both MOMTs in vitro displayed discernible substrate promiscuity towards a range of phenolics in addition to the dominant substrate monolignols, which partially explains their broad effects on grass phenolic biosynthesis. The cell wall structural and compositional changes resulted in up to 30% increase in saccharification yield of the de‐starched rice straw biomass after diluted acid‐pretreatment. These results demonstrate an effective strategy to tailor complex grass cell walls to generate improved cellulosic feedstocks for the fermentable sugar‐based production of biofuel and bio‐chemicals. [ABSTRACT FROM AUTHOR]

Na2S is a key material in sodium‐sulfur batteries and its single‐monolayer film may also be a new 2D material. Herein, the results are first reported by STM, XPS, and DFT simulation that the Na2S single‐monolayer film shows different atomic structures depending on the underlying metals, and these structures can be changed by thermal annealing. All structures are well supported by DFT simulation on corresponding Na2S up, down, and standing models, as well as the NaS in‐plane model. Further, a wide bandgap of Na2S single‐monolayer film is measured, which decreases from Au(111) to Ag(111) and Cu(111) due to the different Na2S interactions with metal substrates. Finally, it is demonstrated that dibenzo 18‐crown‐6‐ether molecules can grow on phase VI of Na2S film at room temperature, as compared with preferred metal surfaces and Na2S phase III structure. [ABSTRACT FROM AUTHOR]

Lignin production marked a milestone in vascular plant evolution, and the emergence of syringyl (S) lignin is lineage specific. S-lignin biosynthesis in angiosperms, mediated by ferulate 5-hydroxylase (F5H, CYP84A1), has been considered a recent evolutionary event. F5H uniquely requires the cytochrome b5 protein CB5D as an obligatory redox partner for catalysis. However, it remains unclear how CB5D functionality originated and whether it coevolved with F5H. We reveal here the ancient evolution of CB5D-type function supporting F5H-catalyzed S-lignin biosynthesis. CB5D emerged in charophyte algae, the closest relatives of land plants, and is conserved and proliferated in embryophytes, especially in angiosperms, suggesting functional diversification of the CB5 family before terrestrialization. A sequence motif containing acidic amino residues in Helix 5 of the CB5 heme-binding domain contributes to the retention of CB5D function in land plants but not in algae. Notably, CB5s in the S-lignin-producing lycophyte Selaginella lack these residues, resulting in no CB5D-type function. An independently evolved S-lignin biosynthetic F5H (CYP788A1) in Selaginella relies on NADPH-dependent cytochrome P450 reductase as sole redox partner, distinct from angiosperms. These results suggest that angiosperm F5Hs coopted the ancient CB5D, forming a modern cytochrome P450 monooxygenase system for aromatic ring meta-hydroxylation, enabling the reemergence of S-lignin biosynthesis in angiosperms., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Solar-energy-driven photoreduction of CO 2 is promising in alleviating environment burden, but suffers from low efficiency and over-reliance on sacrificial agents. Herein, rhenium (Re) is atomically dispersed in In 2 O 3 to fabricate a 2Re-In 2 O 3 photocatalyst. In sacrificial-agent-free photoreduction of CO 2 with H 2 O, 2Re-In 2 O 3 shows a long-term stable efficiency which is enhanced by 3.5 times than that of pure In 2 O 3 and is also higher than those on Au-In 2 O 3 , Ag-In 2 O 3 , Cu-In 2 O 3 , Ir-In 2 O 3 , Ru-In 2 O 3 , Rh-In 2 O 3 and Pt-In 2 O 3 photocatalysts. Moreover, carbon-based product of the photoreduction overturns from CO on pure In 2 O 3 to CH 3 OH on 2Re-In 2 O 3 . Re promotes charge separation, H 2 O dissociation and CO 2 activation, thus enhancing photoreduction efficiency of CO 2 on 2Re-In 2 O 3 . During the photoreduction, CO is a key intermediate. CO prefers to desorption rather than hydrogenation on pure In 2 O 3 , as CO binds to pure In 2 O 3 very weakly. Re strengthens the interaction of CO with 2Re-In 2 O 3 by 5.0 times, thus limiting CO desorption but enhancing CO hydrogenation to CH 3 OH. This could be the origin for photoreduction product overturn from CO on pure In 2 O 3 to CH 3 OH on 2Re-In 2 O 3 . The present work opens a new way to boost sacrificial-agent-free photoreduction of CO 2 ., (© 2024 Wiley‐VCH GmbH.)

The pressure dependent reaction mechanism of CO 2 hydrogenation over In 2 O 3 was investigated. CO 2 hydrogenation on In 2 O 3 can produce methanol only at high pressure, while the atmospheric pressure operation leads to the formation of CO. The conversion from HCOO* to H 3 CO* is accelerated at high pressure, leading to the formation of methanol with the formate route (CO 2 * → HCOO* → H 3 CO* → H 3 COH).