Photocatalytic valorisation of advanced biomass model compounds

The use of semiconductor- mediated photocatalysis for the valorisation of biomass is an area of literature which has gained traction1–6, using raw biomass gives rise to issues when it comes to solubility of substrate and also light penetration considering a turbid solution. The use of model compounds which are fashioned on the linkages which are found in lignin and biomass as a whole would give a more representative picture of how the catalytic system can be honed and the parameters defined. Herein, a hexameric lignin model compound which has been synthesised using a simplistic synthetic approach which is widely accessible to others in the field, following synthesis of the representative model titanium dioxide-mediated photocatalysis. Complete consumption of the model compound was observed in around 1 hour of irradiation with products and pathways proposed using advanced analytical techniques. Moving beyond this lignin model, the use of carbohydrate chemistry for the synthesis of more realistic biomass model compounds have also been investigated, a small library of phenyl glycosidic analogues have been produced and some of their reactions with TiO2. The use of this type of model compound with photocatalysis is an area of research which has previously not been examined and considering this is one of the major forms of how raw biomass is found following extraction, it in conjunction with the hexameric lignin model study will give a comprehensive overview of the reactions and pathways involved in the valorisation of biomass. Fig. 1. Photocatalytic degradation of hexameric lignin model compound.