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

Valeria Pappalardo; Yassine Remadi; Laura Cipolla; Nicola Scotti; Nicoletta Ravasio; Federica Zaccheria

doi:10.3389/fchem.2022.1057461

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

Front Chem. 2022 Nov 2:10:1057461. doi: 10.3389/fchem.2022.1057461. eCollection 2022.

Authors

Valeria Pappalardo¹, Yassine Remadi², Laura Cipolla², Nicola Scotti¹, Nicoletta Ravasio¹, Federica Zaccheria¹

Affiliations

¹ CNR Institute of Chemical Sciences and Technologies "G. Natta", Milano, Italy.
² Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy.

Abstract

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 SiO₂, SiO₂-Al₂O₃, SiO₂-ZrO₂, ZrO₂ and the corresponding bare oxides/mixed oxides were tested, together with a sulfated zirconia system (ZrO₂-SO₃H) 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.

Keywords: ZrO2; chitin; chitosan; solid acids; sulfated catalyst.