Room-temperature photosynthesis of propane from CO2 with Cu single atoms on vacancy-rich TiO2

Abstract

Photochemical conversion of CO2 into high-value C2+ products is difficult to achieve due to the energetic and mechanistic challenges in forming multiple C-C bonds. Herein, an efficient photocatalyst for the conversion of CO2 into C3H8 is prepared by implanting Cu single atoms on Ti0.91O2 atomically-thin single layers. Cu single atoms promote the formation of neighbouring oxygen vacancies (VOs) in Ti0.91O2 matrix. These oxygen vacancies modulate the electronic coupling interaction between Cu atoms and adjacent Ti atoms to form a unique Cu-Ti-VO unit in Ti0.91O2 matrix. A high electron-based selectivity of 64.8% for C3H8 (product-based selectivity of 32.4%), and 86.2% for total C2+ hydrocarbons (product-based selectivity of 50.2%) are achieved. Theoretical calculations suggest that Cu-Ti-VO unit may stabilize the key *CHOCO and *CH2OCOCO intermediates and reduce their energy levels, tuning both C1-C1 and C1-C2 couplings into thermodynamically-favourable exothermal processes. Tandem catalysis mechanism and potential reaction pathway are tentatively proposed for C3H8 formation, involving an overall (20e− – 20H+) reduction and coupling of three CO2 molecules at room temperature.

Graphdiyne (CnH2n−2) coupled with ZnCo-MOF double S-scheme heterojunction forms an efficient electron transport layer and its characterizationvia in situXPS

“…Thus, the electrons on the conduction band of GDY can be completely reduced to H 2 by H + . [68][69][70]…”

Intermediates and their conversion into highly selective multicarbons in photo/electrocatalytic CO2 reduction reactions

“…The mechanism study revealed that the stoichiometric fraction of sodium ions (Na + ) in TNTs strongly influenced the formation of hydrocarbons, and the copper (Cu) deposition was significant in the timely trapping of the transient methyl radical (CH 3 ˙), which was one of the prerequisites for C–C coupling and formation of multicarbon products. Recently added, Wang, Xiong, and Zhou 124 constructed homologous catalyst system, Cu single atoms on Ti 0.91 O 2 atomically thin single layers (Cu-Ti-V O /Ti 0.91 O 2 -SL), which exhibited a high electron- and product-based selectivity for C 3 H 8 and total C 2+ hydrocarbons (Fig. 23b–e).…”

Defect Chemistry in 2D Atomic Layers for Energy Photocatalysis

“…Building 2D atomic layer structures has been regarded as an appealing strategy to tune the charge separation and surface catalysis reactions. − The limited thickness of the 2D atomic layer favors the rapid bulk charge migration to the surface, boosting the bulk charge separation efficiency . The high ratio of surface atoms to entire atoms in 2D atomic layers may offer abundant unsaturated coordination sites to involve in the catalysis reaction .…”