Metal‐Free Photocatalytic Hydrogenation Using Covalent Triazine Polymers

Abstract

Photocatalytic hydrogenation of biomass‐derived organic molecules transforms solar energy into high‐energy‐density chemical bonds. Reported herein is the preparation of a thiophene‐containing covalent triazine polymer as a photocatalyst, with unique donor‐acceptor units, for the metal‐free photocatalytic hydrogenation of unsaturated organic molecules. Under visible‐light illumination, the polymeric photocatalyst enables the transformation of maleic acid into succinic acid with a production rate of about 2 mmol g−1 h−1, and furfural into furfuryl alcohol with a production rate of about 0.5 mmol g−1 h−1. Great catalyst stability and recyclability are also measured. Given the structural diversity of polymeric photocatalysts and their readily tunable optical and electronic properties, metal‐free photocatalytic hydrogenation represents a highly promising approach for solar energy conversion.

An Account of the Catalytic Transfer Hydrogenation and Hydrogenolysis of Carbohydrate‐Derived Renewable Platform Chemicals over Non‐Precious Heterogeneous Metal Catalysts

“…The process is called proton‐coupled electron transfer (PCET), and using this process >99.0 % HMF conversion and 99 % 2,5‐Bis‐(hydroxymethyl)furan (BHMF) selectivity were observed. Li and coworkers prepared thiophene‐containing covalent triazine polymer (CTP−Th) and employed it as a photocatalyst for the hydrogenation of FUR to FOL under visible light irradiation using a 300 W Xe lamp equipped with a 420 nm cutoff filter [86] …”

“…[84] visible light irradiation using a W Xe lamp equipped with a nm cutoff filter. [86] The reaction was performed in aqueous solution in the presence of ascorbic acid as a sacrificial electron donor. The catalytic data revealed the FOL production rate of 0.5 mmol g À 1 h À 1 .…”

State‐of‐the‐Art Advancements in Photocatalytic Hydrogenation: Reaction Mechanism and Recent Progress in Metal‐Organic Framework (MOF)‐Based Catalysts

“…Hu and colleagues reported visible-light-photocatalytic hydrogenation of maleic acid and furfuryl on a metal-free thiophene-containing CTP with high production rate. [16] MOFs, as a novel type of porous crystalline porous materials constructed from metal or metal clusters interconnected by organic ligands, featured with high specific surface areas, tunable pore structure, [17] versatile structure design, [18] have emerged as promising photocatalysts in the applications of organic degradation and transformation, [19] water splitting [20] and carbon dioxide (CO 2 ) reduction. [21] Because MOFs possess the following advantages.…”

“…Hu and colleagues reported visible‐light‐photocatalytic hydrogenation of maleic acid and furfuryl on a metal‐free thiophene‐containing CTP with high production rate. [ 16 ]…”

Electronic Tuning of Covalent Triazine Framework Nanoshells for Highly Efficient Photocatalytic H2O2 Production

“…[20][21][22] Despite the potential, their demonstrated photocatalytic activities were still unsatisfactory for practical applications.Covalent triazine frameworks (CTFs), as a new class of nitrogen-rich organic photocatalysts, have recently emerged owing to their excellent photocatalytic activities and stability for photocatalytic water splitting, [23][24][25][26] CO 2 reduction, [27][28] N 2 fixation, [29] and organic transformation. [30][31][32] In principle, their chemical and electronic structures can be precisely tuned by varying the corresponding precursors and synthetic routes, making them a versatile platform for designing photocatalysts on demand. [33] Notably, CTFs have intrinsic structural similarity to the polymeric skeletons of g-C 3 N 4 , both of which are constructed from primary triazine units.…”