Recycled carbon (RC) materials made functional: An efficient heterogeneous Mn-RC catalyst

•A Mn-catalyst was synthesized by covalent grafting onto pyrolytic carbon surface.•The pyrolytic carbon which used as supporting matrix was derived from waste tyres.•It was active, for degradation of methyl orange with NaIO4, stable and recyclable.

A MnII-Schiff-base catalyst was synthesized and covalently immobilized onto Pyrolytic Carbon surface from waste tyres (PCox), resulting in the heterogeneous catalyst MnII-L@PCox which was evaluated for degradation of methyl orange (MO) using NaIO4 as oxidant. Importantly, no additive as co-catalyst was needed. For comparison, a reference heterogeneous catalyst MnII-L@ACox was also tested, using Activated Carbon (ACox) as carbon matrix. The catalytic and recyclability data of MnII-L@PCox catalyst demonstrate that it is superior, in terms of TONs and TOFs vs.MnII-L@ACox. To study the reaction path, electron paramagnetic resonance spectroscopy was used to monitor the redox evolution of the Mn-centers. Furthermore, a full mapping of the catalytic degradation of MO and product formation was carried out using LC-MS and HPLC. Combining catalytic and spectroscopic data we discuss the protective effect of the PCox matrix on Mn-centers; it allows their rapid redox evolution to higher oxidation states.

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