AUTHOR=Pappalardo Valeria , Remadi Yassine , Cipolla Laura , Scotti Nicola , Ravasio Nicoletta , Zaccheria Federica 

TITLE=Fishery waste valorization: Sulfated ZrO2 as a heterogeneous catalyst for chitin and chitosan depolymerization

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.1057461

DOI=10.3389/fchem.2022.1057461

ISSN=2296-2646

ABSTRACT=<p>Chitin and chitosan are abundant unique sources of biologically-fixed nitrogen mainly derived from residues of the fishery productive chain. Their high potential as nitrogen-based highly added-value platform molecules is still largely unexploited and a catalytic way for their valorization would be strongly desirable within a biorefinery concept. Here we report our results obtained with a series of heterogeneous catalysts in the depolymerization of chitosan and chitin to acetylglucosamine. Copper catalysts supported on SiO<sub>2</sub>, SiO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>-ZrO<sub>2</sub>, ZrO<sub>2</sub> and the corresponding bare oxides/mixed oxides were tested, together with a sulfated zirconia system (ZrO<sub>2</sub>-SO<sub>3</sub>H) that revealed to be extremely selective towards glucosamine, both for chitosan and chitin, thus giving pretty high yields with respect to the values reported so far (44% and 21%, respectively). The use of a heterogeneous catalyst alone, without the need of any additives or the combination with a mineral acid, makes these results remarkable.</p>