Mesoporous SBA‐15 Supported CdS through Organosilane Ligand for Photo Driven Cleavage of Aryl Ether in Lignin and its Model Compound

Mesoporous silica (SBA‐15) was synthesized hydrothermally followed by calcination and then functionalization with 3‐(triethoxysilyl)‐1‐propanethiol through surface grafting. The thiol moiety of the grafted ligand was utilized for the uniform anchoring of cadmium into the channels of the material. The synthesised material was subjected for its photo catalytic applications after characterization through standard characterization protocol. The synthesised mesoporous silica (i.e. SAB‐15), ligand modified material (i.e.SBA‐15‐S and Cd loaded ( i.e. SAB‐15‐CdS) materials were characterized through standard characterization protocol like powder XRD, FT‐IR, UV‐DRS, MAS NMR, N2 sorption, FE‐SEM, HR‐TEM and TG‐DTA studies. After successful characterization, the screening of the catalyst was carried out on a model reaction involving photo catalytic cleavage of α‐O‐4 aryl ether linkage present in benzyl phenyl ether, which is an important lignin model compound. The catalyst exhibited good efficiency along with the selectivity for desired monoaromatic platform chemicals. The synthesized catalyst was also carried out for the photo catalytic depolymerization of alkali lignin at the optimized reaction conditions which further showed the promising results for getting value added chemicals from lignin. The reaction products were characterized by using Gas chromatography‐mass spectrometry (GC‐MS) techniques. Mesoporous silica with CdS modification (i. e. SBA‐15‐CdS) prepared through the stepwise procedure involving hydrothermal synthesis of SBA‐15, ex‐situ grafting of mercapto silanes followed by the impregnation of cadmium ion into the channels of pre functionalized SBA‐15. The final prepared material with high surface area and pore volume (i. e. SBA‐15‐CdS) was employed as heterogeneous photo‐catalyst for photo catalytic cleavage of aryl ether bond present in alkali lignin and in benzyl phenyl ether which is a lignin model compound with α‐O‐4 linkage.