Interconversion and selective reactivity of sulfur dioxide reduction intermediates inserted on graphene oxide

Graphene oxide, MPGO, was obtained by oxidation of graphite microparticles by a H 2 SO 4 /KMnO 4 /H 2 O 2 mixture followed by thermal exfoliation. Non‐thermal plasma treatment of MPGO under SO 2 atmosphere resulted in the insertion of the oxidized intermediates only. Refluxing this material in CS 2 (46 °C) showed sulfur elimination and interconversion of the oxidized into non‐oxidized intermediates with an energetic barrier of ΔG ‡  = 25.81 kcal mol −1 without decarboxylation . The episulfide content in modified MPGO increases with respect to the oxidized intermediates when increasing temperature. Modification of MPGO with SO 2 at 630 °C presented exclusively the non‐oxidized intermediate . These results support the hypothesis that there are two major reactions with different energetic demand in the SO 2 reduction on carbons: desulfurization and decarboxylation . The selectivity of thiolysis and aminolysis towards the intermediates inserted in the MPGO matrix allowed the amino‐thiolysis of a sample containing both intermediates with the insertion of the amino group on the episulfide site followed by an intramolecular thiolysis with double functionalization of the matrix. Copyright © 2016 John Wiley & Sons, Ltd.