Lignin represents the most abundant and sustainable aromatic
resource
to produce value-added aromatics. However, an efficient and selective
cleavage of recalcitrant C–C bonds in lignin under mild conditions
remains challenging. Photocatalysis has emerged as a promising strategy
for such a C–C bond cleavage under ambient conditions, although
the activity and selectivity need to be further improved. Herein,
using polyimide as a photocatalyst, we report an efficient and selective
C–C bond cleavage in a β-O-4 lignin model under visible
light at room temperature. The lignin model was converted into aromatic
products with >99% substrate conversion and >99% C–C
bond cleavage
selectivity, which are superior to previously reported photocatalytic
systems. Experimental investigations together with theoretical calculations
indicated that the superior performance of the polyimide photocatalyst
was attributed to its strong photooxidation capability and efficient
charge carrier separation efficiency. Mechanistic studies revealed
that the dehydrogenation of the lignin model driven by photogenerated
holes was the rate-determining step. This work provides useful guidance
for the design of high-performance photocatalysts for selective C–C
bond cleavage of lignin.
Polyimide (PI), a typical donor-acceptor polymeric semiconductor, exhibits promising photocatalytic applications owing to their distinct advantages of facile synthesis, easy functionalization and molecularly tunable optoelectronic properties. However, PI in its...
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.