ORR Catalysts Derived from Biopolymers

Abstract

Due to the limited reaction rate of the oxygen reduction reaction (ORR), it is considered as a limiting factor in the performance of fuel cells and metal-air batteries. Platinum is considered the benchmark catalyst for ORR; however, the scarcity of platinum, its high price, the drift phenomenon, its insufficient durability, and its susceptibility to gas poisoning are the reasons for the constant search for new ORR catalysts. Carbon-based catalysts show exceptional promise in this respect considering economic profitability and activity, and, in addition, they have favorable conductivity and often a large specific surface area. The use of chitin, cellulose, lignin, coconut shell particles, shrimp shells, and even hair for this purpose was reported, as they had similar electrochemical activity regarding Pt. Alginate, a natural polymer and a constituent of brown algae, can be successfully used to obtain carbon materials that catalyze ORR. In addition, metal atomic-level catalysts and metal N-doped porous carbon materials, obtained from sodium alginate as a precursor, have been proposed as efficient electrocatalysts for ORR. Except for alginate, other biopolymers have been reported to play an important role in the preparation of ORR catalysts. In this review, recent advances regarding biopolymer-derived ORR catalysts are summarized, with a focus on alginate as a source.

Current significance and future perspective of 3D-printed bio-based polymers for applications in energy conversion and storage system

“…Besides that, combined with post-treatment processes such as pyrolysis, several bio-based polymers containing natural impurities (PLA), nitrogen (chitin, chitosan, and lignin), and sulfur (keratin) were reported to serve as excellent carbon-based catalyst and electrode material. These inherent properties act as a dopant or catalytic active sites for photo- and electrochemical conversion processes [ 19 , 79 ].…”

“…The N atom acts as dopant that could link to the improvement of the carbon substrate conductivity, contributing to charge transfer within energy devices [ 19 , 147 , 148 ]. Other than that, S atom contained in keratin could also serve the same purpose [ 79 ]. Therefore, the exploration towards other kind of bio-based polymers with diverse functional groups may be an interesting direction for the development of 3D-printed energy devices.…”

Enzymolytic Lignin-Derived N-S Codoped Porous Carbon Nanocomposites as Electrocatalysts for Oxygen Reduction Reactions

“…In order to achieve carbon peaking and carbon neutrality goals, various countries have made tremendous efforts to develop advanced energy conversion and storage equipment [1]. Among these, fuel cells have attracted much attention due to their high energy density and high specific capacity, and their performance is superior to commercial Li-ion batteries [2]. However, the slow cathodic kinetics of oxygen reduction reaction (ORR) greatly limits the overall reaction rate of the battery, resulting in insufficient energy conversion efficiency of zinc air batteries [3,4], which also affects the further improvement of battery performance.…”

Recent Advances in Zeolites and Porous Materials Applications in Catalysis and Adsorption Processes

“…The oxygen reduction reaction is of utmost importance for fuel cell design. Bio-based carbons are at the forefront of this investigation due to their environmental soundness, conductivity, ease of doping and textural features, as summarized by Rupar et al [10]. Biopolymers are selected as readily available precursors for carbon-designed ORR electrode materials.…”

“…Biopolymers are selected as readily available precursors for carbon-designed ORR electrode materials. The preparation procedure for these functional carbons governs porosity development and influences their performance to a large extent [10].…”