Selenium and nitrogen co-doped biochar as an efficient metal-free catalyst for oxidation of aldehydes

Abstract

In attempt to develop a metal-free and bio-based catalyst, herein we report a facile procedure for the synthesis of a novel Se and N-doped biochar. In this regard, 2,4,6-triselenocyanato-1,3,5-triazine (TSC-TA) was prepared from reaction of KSeCN and 2,4,6-trichloro-1,3,5-triazine and used as a N and Se source. Lemone verbena, that is an abundant local plant, on the other hand, was applied as bio-source. Carbonization of a mixture of Lemone verbena and TSC-TA (mass ratio of 6:1) led to the formation of Se and N co-doped biochar with graphitic nature. The as-prepared biochar was then utilized as a metal-free catalyst for the oxidation of aromatic aldehydes to their corresponding carboxylic acids under solvent-free condition. The results indicated high catalytic activity of the catalyst, which was superior to non-doped counterpart. Furthermore, the catalyst was recyclable and could be recovered and recycled for seven runs.