Preparation of Manganese Lignosulfonate and Its Application as the Precursor of Nanostructured MnOx for Oxidative Electrocatalysis

Klaudia Gawluk,Grzegorz Milczarek,Anna Modrzejwska-Sikorska,Tomasz Rębiś

doi:10.3390/catal7120392

Klaudia Gawluk, Grzegorz Milczarek + Show 2 more

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https://doi.org/10.3390/catal7120392

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Abstract

The synthesis of manganese lignosulfonates by a two-step method has been reported. It was based on the conversion of technical sodium derivative of lignosulfonate to its hydrogen form i.e., lignosulfonic acid and its further reaction with manganese hydroxide. The obtained product was electroactive, and could be applied as the precursor of electroactive manganese oxide. The product showed a reversible redox activity in the potential range of 0 to 1 V vs. an Ag/AgCl reference electrode. The electroactivity of the obtained product can be tentatively assigned to the redox activity of both the electrodeposited MnOx and the presence of lignosulfonate-derived quinones since the energy dispersive spectroscopy (EDS) confirmed the presence of organic matter in the deposit. It also showed substantial electrocatalytic activity towards the anodic oxidation of hydrogen peroxide. This suggests that manganese lignosulfonates could be a valuable compound for the electrochemical preparation of electroactive layers that are suitable in the development of electrochemical sensors.

Highlights

The continuously increasing need for value-added products from cheap and renewable resources has resulted in considerable interest in biopolymers and biomacromolecules as the base for functional polymer compositions, hybrid and composite materials showing unique features.Lignin, after cellulose, is the second most abundant naturally occurring biopolymer that is binding cellulose fibers together in plant cells
We reported several chemically modified electrodes based on technicalmodified lignins that could bebased used for technical lignins that could be used for both oxidative and reductive electrocatalysis
A novel electrocatalytic film comprised of manganese oxide and lignosulfonate was prepared from the corresponding manganese lignosulfonate by the anodic oxidation at mild conditions

Summary

Introduction

The continuously increasing need for value-added products from cheap and renewable resources has resulted in considerable interest in biopolymers and biomacromolecules as the base for functional polymer compositions, hybrid and composite materials showing unique features.Lignin, after cellulose, is the second most abundant naturally occurring biopolymer that is binding cellulose fibers together in plant cells. From the chemical structure viewpoint, the parent lignin is an amorphous, polyphenolic material arising from enzyme-mediated dehydrogenative polymerization of three phenylpropanoid monomers, coumaryl, coniferyl, and sinapyl alcohol [1]. It is strongly interacting with cellulose via hydrogen bonding in living plants and is insoluble in any solvent. The technologies that are focused on getting cellulose or cellulosic materials e.g., paper are based on chemical composition able to digest lignin and separate it from cellulose This results in the production of huge amounts of technical lignins, which are chemical derivatives of the parent lignin that are characterized by a chemically functionalized structure, lower molecular weight, and altered solubility in water and/or organic solvents. Like parent lignin, lignosulfonates are polyphenolic compounds, and show reducing properties, i.e., they can be Catalysts 2017, 7, 392; doi:10.3390/catal7120392 www.mdpi.com/journal/catalysts

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