An integration system derived from LDHs for CO2 direct capture and photocatalytic coupling reaction

Aiming at integration of CO 2 capture and utilization, we put forward a nanocatalyst for coupling photocatalytic CO 2 reduction with 5-hydroxymethylfurfural (5-HMF) oxidation. Specifically, we synthesize a carbonate-type CuCoAl-layered double hydroxide (LDH) to pre-enrich the raw material of the half reduction reaction. In the inert atmosphere, CO 3 2− located in the interlayers realized in situ reduction catalyzed by the metal cations on the layers, and this was coupled with 5-HMF oxidation catalyzed by the hydroxyl sites, thus generating CO as a reduction product and 2.5-furandiformaldehyde (DFF), 5-formyl-2-furanacarboxylic acid (FFCA), and 2.5-furan dicarboxylic acid (FDCA) as oxidation products. A series of in situ Fourier transform infrared (FTIR) spectroscopy with assistance of 13 C labeling characterizations clarified the above in situ transformation process and further revealed the important role of tuning the electronic structure by selectively etching the LDHs layers in promoting catalytic performance. More importantly, the consumed CO 3 2− could be easily supplied by CO 2 in air, which would endowed the nanocatalyst with good recycle performance. • Constructing CO 3 2− -CuCoAl-LDHs for CO 2 reduction and 5-HMF oxidation coupling • Selective etching laminate cations is conducive to improving the performance • Directly supplying the consumed CO 3 2− from CO 2 in air endows good reusability • Designing in situ characterizations to reveal coupling mechanism under light Under the background of global efforts to be carbon neutral, comprehensive utilization of CO 2 and high-value conversion of biomass have become the mainstream trend in the field of energy research. Herein, we propose a new concept regarding the integration of CO 2 direct capture, utilization, and biomass high-value conversion, and thus we construct a carbonate-type layered double hydroxide (LDH) catalyst, which opens a green path not only for CO 2 capture, utilization, and storage (CCUS) technology but also for the synthesis of fine chemicals. Moreover, the smart employment of LDHs taps the application potential of 2D materials and simultaneously provides a reference for exploring a novel coupling process associated with traditional carbonate decomposition, which will be of great significance for reducing rigid CO 2 . A carbonate-type CuCoAl-layered double hydroxide (LDH) was synthesized to pre-enrich the raw material of the half reduction reaction. In the inert atmosphere, CO 3 2− located in the interlayers realized in situ reduction, which was coupled with 5-HMF oxidation, thus generating CO as reduction product and 2.5-furandiformaldehyde (DFF), 5-formyl-2-furanacarboxylic acid (FFCA), and 2.5-furan dicarboxylic acid (FDCA) as oxidation products. More importantly, the consumed CO 3 2− could be easily supplied by CO 2 in air, which would endow the nanocatalyst with good recycle performance.