Sewage Sludge-Derived Materials as Efficient Catalysts for the Selective Production of Vanillin from Isoeugenol

Sewage sludge, a byproduct from wastewater treatment, is one of the most abundant residues in urban areas. Its high carbon and ash content make it an interesting waste to be potentially converted into novel materials via carbonization. In this work, we report the use of a sewage sludge material as the catalyst for the selective oxidation of isoeugenol to vanillin. High conversion (80%) and selectivity to vanillin (65%) were obtained after 1 h of reaction. Excellent material stability was observed after different catalytic reuses increasing the effectiveness of this material for catalytic applications.