Tailoring collaborative N–O functionalities of graphene oxide for enhanced selective oxidation of benzyl alcohol

Benzaldehyde (BzH) is an important chemical for industrial feedstock. However, the conventional pro-duction processes heavily rely on precious metal catalysts and bring about unavoidable pollution issues.Here we report a new catalytic process to use N-doped graphene oxide (NGO) as the catalyst foroxidation of benzyl alcohol (BzOH) into BzH by an environmentally benign oxidant, peroxymonosulfate(PMS). Different approaches are developed to synthesize carbonylated NGO, which shows higher cata-lytic efficiency than C]O-deficient NGO. The optimized catalyst could achieve 96% BzOH conversion andunprecedented 82% BzH yield under mild temperature (50 C), superior to some precious metal catalystsreported. Experimental studies unveil the indispensable roles of pyridinic N and ketonic C]O groups informing an electron bridge between BzOH and PMS for non-radical oxidation, or separately inducingradical oxidation. The non-radical oxidation process is more selective in yielding BzH. Furthermore, theyielded BzH is free from over-oxidation into benzoic acid under various reaction conditions, because theradicals preferentially react with BzOH other than BzH and the BzH can hardly adsorb on graphenesheets, thus inhibiting its further oxidation. This work provides a cheap material and mechanic under-standing of carbocatalysis for green organic synthesis with environmental and economic perspectives.Jiaquan Lia, Fuping Lia, Qi Yanga, Shaobin Wangb, Hongqi Sunc, Qingning Yangd, Junwang Tangd, Shaomin Li