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Production of p-xylene (PX) via a broad biomass-derived furan cycloaddition has received incremental interest because of its renewable character. To date, the [4 + 2] cycloaddition reaction of furan derivatives with acrylic acid (AA) to synthesize PX has been achieved mainly by thermo-catalysis, but the stern reaction conditions usually lead to high energy costs. Herein, we report a copper-mediated decarboxylative cycloaddition within PW@HKUST-1 under visible-light irradiation to realize rapid synthesis of PX with 92.6% yield in 3 h under atmospheric pressure. Preliminary mechanistic studies reveal a radical decarboxylation process via ligand-to-metal charge transfer (LMCT) that initiates the [4 + 2] cycloaddition under visible-light irradiation. This work suggests that photoexcited [4 + 2] cycloaddition could be a cost-effective strategy for the synthesis of biomass-derived PX. [ABSTRACT FROM AUTHOR]

As one of the most commonly bulky chemicals, chlorine is conventionally manufactured by electrolysis of NaCl solution in the chlor–alkali process, which requires a huge supply of electrical energy. The photocatalytic route to produce chlorine by using solar energy and NaCl solution offers a promising strategy to reduce energy consumption and bring economic benefits. Herein, it was found that the introduction of CO2 would enhance the productivity of Cl2 from 8.24 μmol⋅h−1 to 39.6 μmol⋅h−1 in NaCl solution over BiOCl. Experimental studies reveal that the CO2 species (CO32−) entered into the crystal texture of BiOCl and the interlayer space between [Bi2O2]2+ slabs were increased and distorted, accelerating the cycle of Cl species. Besides, the cycle of carbonate species also existed and accelerated the reaction efficiency of Cl− oxidation to Cl2. This work provides a new feasible method of using abundant CO2 resources to accelerate the process of chlorine production via photocatalysis. [ABSTRACT FROM AUTHOR]

The construction of aromatic skeleton structures by the Diels–Alder reaction is a synthetic route to obtain substitutes for petrochemical products using biomass as a raw material. In this work, a class of SiW@MIL-100(Fe)-n (n = 1–4) catalysts containing silicotungstic acid (SiW) encaged in MIL-100(Fe) was synthesized for the mimic synthesis of p-xylene (PX). SiW@MIL-100(Fe)-3 was applied to catalyze the reaction of 2,5-dimethylfuran and acrylic acid (AA) to give aromatic products (yield 94%, PX yield = 80.1%) at 140 °C under ambient pressure. The synergistic effect between the metal centers and Lewis/Brønsted acid was increased due to the confinement effect in the cage of MIL-100(Fe). The Fe(III) sites catalyzed the decarboxylation of AA via a free radical process, avoiding the formation of the 2,5-dimethylbenzoic acid intermediate. Two types of acid sites along with the reactants as well as the reversibly adsorbed water promoted the formation of hydrogen bonds with protons from SiW, which accelerated the dehydration reaction. This strategy provides a route for the construction of aromatic skeletons from biomass derivatives by MOF-based solid acid catalysts. [ABSTRACT FROM AUTHOR]

Carbon dioxide anion radical (CO 2 •- ) can act as a versatile single electron reductant, but its generation pathways are quite limited. Herein, we demonstrate that oxalic acid (OA) could be effectively and continuously utilized to produce CO 2 •- over Bi(C 2 O 4 )OH, a novel photocatalyst, under light irradiation. Bi(C 2 O 4 )OH would proceed with self-redox reactions under the light irradiation producing CO 2 •- , through the oxidation of C 2 O 4 2- . OA in the solution could recoordinate with Bi 3+ , thus maintaining the structure of the photocatalysts and the stability of the reactions. Benefiting from the fast reaction between CO 2 •- and O 2 in forming • O 2 - , hydrogen peroxide (H 2 O 2 ) would be efficiently produced (219.0 μmol/h). This study proposes a novel approach for harnessing OA containing wastewater and explores its potential application in the efficient production of H 2 O 2 .

As one of the most commonly bulky chemicals, chlorine is conventionally manufactured by electrolysis of NaCl solution in the chlor-alkali process, which requires a huge supply of electrical energy. The photocatalytic route to produce chlorine by using solar energy and NaCl solution offers a promising strategy to reduce energy consumption and bring economic benefits. Herein, it was found that the introduction of CO 2 would enhance the productivity of Cl 2 from 8.24 μmol⋅h -1 to 39.6 μmol⋅h -1 in NaCl solution over BiOCl. Experimental studies reveal that the CO 2 species (CO 3 2- ) entered into the crystal texture of BiOCl and the interlayer space between [Bi 2 O 2 ] 2+ slabs were increased and distorted, accelerating the cycle of Cl species. Besides, the cycle of carbonate species also existed and accelerated the reaction efficiency of Cl - oxidation to Cl 2 . This work provides a new feasible method of using abundant CO 2 resources to accelerate the process of chlorine production via photocatalysis., (© 2023 Wiley-VCH GmbH.)