Photocatalytic conversion of sodium lignosulfonate into vanillin using mesoporous TiO2 derived from MIL-125

Lignin and metal–organic frameworks: mutual partners on the road to sustainability

“…Meanwhile, its mesoporous structure provided a pathway for the transport of carriers and products, which promoted the degradation of lignin and the selectivity for the products. 122 These novel composites obtained by calcination or carbonization of MOFs as a precursor can greatly improve the degradation rate of lignin. 84,116,123 Given that the doped N can act as an electron acceptor to assist the carbon atoms in the metal lattice, these materials can show excellent catalytic performance.…”

“…Qiu et al obtained vanillin in appreciable yields in the photocatalytic conversion of sodium lignosulfonate from MOF metal oxides generated by the high-temperature calcination of MIL-125(Ti). 122 Calcination increased the specific surface area of MOF, which provided sufficient active sites for the catalytic process. Meanwhile, its mesoporous structure provided a pathway for the transport of carriers and products, which promoted the degradation of lignin and the selectivity for the products.…”

Striding the threshold of photocatalytic lignin-first biorefining via a bottom-up approach: from model compounds to realistic lignin

“…It thus is disclosed that photocatalytic lignin conversion usually involves the cession of its subunits and/or decoration of active groups. 36 Generally, there are three prevalent pathways for the photocatalytic cleavage of lignin subunits such as β-O-4′ linkages: 35,[37][38][39] (1) reductive cleavage initiated by electrons or reductive agents; (2) oxidative cleavage promoted by holes or oxidative species; and (3) charge carrier-driven redox neutral cleavage combined with electron-hole pairs.…”

“…During the photocatalytic conversion of sodium lignosulfonate, the yield of vanillin over mesoporous TiO 2 with regular pancake-like morphology was 2.1 mg g −1 , in which the mesoporous structure allowed for the transport of photocarriers and h + / • O 2 − triggered the transformation of lignosulfonate to vanillin. 39 Lin et al discussed lignin conversion using Zn 4 In 2 S 7 (ZIS) as a photocatalyst under visible light irradiation to gain func- tional aromatic hydrocarbons, in which the thiol groups played a key role in the photocatalytic system. 81 During the degradation of the dioxasolv birch lignin, a high yield of aromatic monomers was approximately 18.4 wt% via two detached mechanisms for β-O-4′ bond cleavage (Fig.…”

“…During the photocatalytic conversion of sodium lignosulfonate, the yield of vanillin over mesoporous TiO 2 with regular pancake-like morphology was 2.1 mg g −1 , in which the mesoporous structure allowed for the transport of photocarriers and h + /˙O 2 − triggered the transformation of lignosulfonate to vanillin. 39…”