The catalytic oxidative dehydrogenation of lactates with molecular oxygen is a promising yet challenging route for producing high-value pyruvates from biomass. Here we report a simple synthetic strategy for preparing nitrogen-doped carbon nanosheets (NCNs) starting from two abundant precursors, cheap melamine and glucose, and using a simple thermal-annealing process. The resulting NCNs feature numerous edges and holes for anchoring vanadium oxides (V-NCNs). This creates cooperative catalytic sites that boost the catalytic oxidation of ethyl lactate to ethyl pyruvate. Additionally, we systematically studied the surface nitrogen species of NCNs by varying the pyrolysis temperature, and found that the active pyridinic N-oxide species formed in a high thermal-annealing treatment, acting synergistically with vanadium active sites in converting ethyl lactate with oxygen into ethyl pyruvate under mild conditions.