CuMoxW(1-x)O4 Solid Solution Display Visible Light Photoreduction of CO2 to CH3OH Coupling with Oxidation of Amine to Imine

Abstract

<jats:p>The photoreduction of carbon dioxide (CO2) to valuable fuels is a promising strategy for the prevention of rising atmospheric levels of CO2 and the depletion of fossil fuel reserves. However, most reported photocatalysts are only active in the ultraviolet region, which necessitates co-catalysts and sacrificial agents in the reaction systems, leading to an unsatisfied economy of the process in energy and atoms. In this research, a CuMoxW(1-x)O4 solid solution was synthesized, characterized, and tested for the photocatalytic reduction of CO2 in the presence of amines. The results revealed that the yield of CH3OH from CO2 was 1017.7 μmol/g under 24 h visible light irradiation using CuW0.7Mo0.3O4 (x = 0.7) as the catalyst. This was associated with the maximum conversion (82.1%) of benzylamine to N-benzylidene benzylamine with high selectivity (&gt;99%). These results give new insight into the photocatalytic reduction of CO2 for valuable chemical products in an economic way.</jats:p>

Visible Light-Active Ternary Heterojunction Photocatalyst for Efficient CO2 Reduction with Simultaneous Amine Oxidation and Sustainable H2O2 Production

“…The detailed reaction pathways are shown below NCZ + h υ 0.25em → NCZ * + 0.25em normale cond − + normalh val + PhCH 2 NH 2 + 2 normalh val + → Ph − CH = NH + 2 normalH cond + CO 2 + 2 normalH cond + + 2 normale cond − → HCOOH HCOOH + 2 normalH cond + + 2 normale cond − → HCHO + normalH 2 normalO HCHO + 2 normalH cond + + 2 normale cond − → CH 3 OH Ph − CH…”

“…However, some articles are found to report on photocatalytic H 2 evolution coupled with selective organic oxidation. , Yang et al illustrated the simultaneous photocatalytic CO 2 reduction along with oxidation of amines into imines using the Cu/TiO 2 photocatalyst under UV light (λ = 365 nm) . Furthermore, Luo et al developed a CuMo x W (1– x ) O 4 photocatalyst to reduce CO 2 into methanol with the oxidative coupling of amines to imines in the presence of visible light . However, they used 0.6 MPa pressure of CO 2 in this reaction.…”

Unravelling the redox behaviour of a carbon nitride polymer-based ternary heterostructure for CO2 photoreduction promoted by amine coupling

“…Luo et al achieved 82.1% conversion of benzylamine with CO 2 reduction to CH 3 OH at 0.5 MPa using a solid solution of CuMo x W (1− x ) O 4 under visible light. 16 Markushyna et al investigated benzylamine oxidation with CO 2 using a C 3 N 4 semiconductor, but the maximum yield remained at only 34% for N -benzylidene benzylamine. 17 Recently, Wang et al fabricated CdS quantum dot decorated ordered mesoporous carbonaceous frameworks to efficiently reduce CO 2 with the oxidative coupling of amines into imines under visible light irradiation.…”

Dual photocatalysis for CO2 reduction along with the oxidative coupling of benzylamines promoted by Cu/Cu2O@g-C3N4 under visible irradiation

“…In this context, Luo et al O 4 for the oxidation of amines (conversion of benzylamine is 82.1%) into imines (selectivity >99%) with the photoreduction of CO 2 into CH 3 OH at 0.5 MPa in visible light. 24 Markushyna et al investigated various benzylamine oxidations with CO 2 using a g-C 3 N 4 semiconductor, but the maximum yield remained only 34% for Nbenzylidene benzylamine. 25 In continuation of our ongoing research on photocatalytic conversion of CO 2 , 26 herein we report a novel Cu/Cu 2 O@C 3 N 4 (CuCN) heterojunction as a twin functional photocatalyst for the oxidative coupling of benzylamines into the corresponding N-benzylidene benzylamines and the simultaneous reduction of CO 2 into methanol under visible light conditions without using any additional sacricial donor (Scheme 1).…”

“…In this context, Luo et al reported a solid solution of CuMo x W (1− x ) O 4 for the oxidation of amines (conversion of benzylamine is 82.1%) into imines (selectivity >99%) with the photoreduction of CO 2 into CH 3 OH at 0.5 MPa in visible light. 24 Markushyna et al investigated various benzylamine oxidations with CO 2 using a g-C 3 N 4 semiconductor, but the maximum yield remained only 34% for N -benzylidene benzylamine. 25…”