Electrochemical Performance of Hierarchical Porous Carbon Materials Obtained from the Infiltration of Lignin into Zeolite Templates

• Published in: ChemSusChem 2014-05, Vol.7 (5), p.1458-1467
• Main Authors: Ruiz-Rosas, R., Valero-Romero, M. J., Salinas-Torres, D., Rodríguez-Mirasol, J., Cordero, T., Morallón, E., Cazorla-Amorós, D.
• Format: Article
• Language: English
• Subjects: biomass; Carbon; Carbon - chemistry; Electric Capacitance; Electrochemical Techniques; electrochemistry; green chemistry; Lignin; Lignin - chemistry; Microscopy, Electron, Transmission; Oxidation-Reduction; Porosity; Sulfuric Acids - chemistry; Surface Properties; Zeolites; Zeolites - chemistry
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201301408

Hierarchical porous carbon materials prepared by the direct carbonization of lignin/zeolite mixtures and the subsequent basic etching of the inorganic template have been electrochemically characterized in acidic media. These lignin‐based templated carbons have interesting surface chemistry features, such as a variety of surface oxygen groups and also pyridone and pyridinic groups, which results in a high capacitance enhancement compared to petroleum‐pitch‐based carbons obtained by the same procedure. Furthermore, they are easily electro‐oxidized in a sulfuric acid electrolyte under positive polarization to produce a large amount of surface oxygen groups that boosts the pseudocapacitance. The lignin‐based templated carbons showed a specific capacitance as high as 250 F g−1 at 50 mA g−1, with a capacitance retention of 50 % and volumetric capacitance of 75 F cm−3 at current densities higher than 20 A g−1 thanks to their suitable porous texture. These results indicate the potential use of inexpensive biomass byproducts, such as lignin, as carbon precursors in the production of hierarchical carbon materials for electrodes in electrochemical capacitors. No limit for lignin: Hierarchical micro‐/mesoporous carbon materials are prepared by the liquid‐phase impregnation of zeolites with an inexpensive and renewable biopolymer, lignin. High capacitances and an outstanding rate performance are obtained as a result of the ordered arrangement of porosity and the presence of certain electroactive surface oxygen and nitrogen groups.