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.
Selective
synthesis of valuable secondary amines through N-alkylation
of amines with alcohols is an important reaction in the modern industry
but still remains a challenge in the chemical synthesis technique.
Hereby, we report the visible-light-driven photocatalytic N-alkylation
of aniline with benzyl alcohol over defined single Pd–S
x
species in situ coordinated
on a CdS surface. Encouragingly, an aniline conversion of 100% and
an almost 100% product selectivity toward the secondary amine N-benzylaniline are obtained with impressive H2 production (11.8 mmol gcat
–1 h–1). The mechanistic studies reveal that the single
Pd–S
x
species on the CdS surface
can trap photogenerated electrons to endow them with a long lifetime
to benefit the vibrational coupling of the hydrogen adsorption on
Pd–S
x
species and then can serve
as an efficient hydrogen autotransfer shuttle for the hydrogenation
process toward the formation of the secondary amine N-benzylaniline. In addition, the present catalyst possesses good
substrate tolerance for photocatalytic N-alkylation of different alcohols
and substituted amines under optimized conditions. This work offers
an alternative solar-driven catalytic system for the N-alkylation
industry under mild conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.